diff --git a/src/main/frontend/components/general/AssignRolesModal.tsx b/src/main/frontend/components/general/AssignRolesModal.tsx
index 70ff422..04dd619 100644
--- a/src/main/frontend/components/general/AssignRolesModal.tsx
+++ b/src/main/frontend/components/general/AssignRolesModal.tsx
@@ -32,12 +32,12 @@ export default function AssignRolesModal({
                                              user
                                          }: AssignRolesModalProps) {
     const [availableRoles, setAvailableRoles] = useState<Role[]>([]);
-    const [selectedRoles, setSelectedRoles] = useState<Selection>();
+    const [selectedRole, setSelectedRole] = useState<Selection>();
     const [error, setError] = useState<string>();
 
     useEffect(() => {
-        setSelectedRoles(rolesToSelection(user.roles!));
-        UserEndpoint.getAvailableRoles().then((availableRoles) => {
+        setSelectedRole(rolesToSelection(user.roles!));
+        UserEndpoint.getRolesBelow().then((availableRoles) => {
             setAvailableRoles(availableRoles!.map((role) => ({id: role!.toString()})));
         });
     }, []);
@@ -47,15 +47,18 @@ export default function AssignRolesModal({
     }
 
     async function assignRoles() {
-        if (!selectedRoles) return;
+        if (!selectedRole) return;
 
-        let selectedRolesArray = Array.from(selectedRoles).map((role) => role.toString());
+        let selectedRolesArray = Array.from(selectedRole).map((role) => role.toString());
         let result = await UserEndpoint.assignRoles(user.username, selectedRolesArray);
         if (!result) return;
         switch (result) {
             case RoleAssignmentResult.SUCCESS:
                 window.location.reload();
                 break;
+            case RoleAssignmentResult.NO_ROLES_PROVIDED:
+                setError("Select at least one role");
+                break;
             case RoleAssignmentResult.TARGET_POWER_LEVEL_TOO_HIGH:
                 setError("Power level of user too high");
                 break;
@@ -78,9 +81,10 @@ export default function AssignRolesModal({
                         <ModalBody className="flex flex-col gap-2">
                             <Select
                                 items={availableRoles}
-                                selectionMode="multiple"
-                                selectedKeys={selectedRoles}
-                                onSelectionChange={setSelectedRoles}
+                                selectionMode="single"
+                                disallowEmptySelection={true}
+                                selectedKeys={selectedRole}
+                                onSelectionChange={setSelectedRole}
                                 placeholder="Select roles"
                                 renderValue={(items: SelectedItems<Role>) => {
                                     return (
@@ -106,7 +110,7 @@ export default function AssignRolesModal({
                             <Button variant="light" onPress={onClose}>
                                 Cancel
                             </Button>
-                            <Button color="primary" onPress={assignRoles} isDisabled={!selectedRoles}>
+                            <Button color="primary" onPress={assignRoles} isDisabled={!selectedRole}>
                                 Assign roles
                             </Button>
                         </ModalFooter>
diff --git a/src/main/frontend/components/general/UserManagementCard.tsx b/src/main/frontend/components/general/UserManagementCard.tsx
index f12e74a..794d8b6 100644
--- a/src/main/frontend/components/general/UserManagementCard.tsx
+++ b/src/main/frontend/components/general/UserManagementCard.tsx
@@ -2,7 +2,7 @@ import {Card, Dropdown, DropdownItem, DropdownMenu, DropdownTrigger, useDisclosu
 import {DotsThreeVertical} from "@phosphor-icons/react";
 import {useAuth} from "Frontend/util/auth";
 import {useEffect, useState} from "react";
-import {MessageEndpoint, PasswordResetEndpoint, RegistrationEndpoint} from "Frontend/generated/endpoints";
+import {MessageEndpoint, PasswordResetEndpoint, UserEndpoint} from "Frontend/generated/endpoints";
 import {AvatarEndpoint} from "Frontend/endpoints/endpoints";
 import Avatar from "Frontend/components/general/Avatar";
 import ConfirmUserDeletionModal from "Frontend/components/general/ConfirmUserDeletionModal";
@@ -28,30 +28,19 @@ export function UserManagementCard({user}: { user: UserInfoDto }) {
         let keysToBeDisabled: string[] = [];
         MessageEndpoint.isEnabled().then((isEnabled) => {
             if (isEnabled) keysToBeDisabled.push("resetPassword");
-            if (!canUserBeDeleted()) keysToBeDisabled.push("delete")
             if (!user.hasAvatar) keysToBeDisabled.push("removeAvatar");
             setDisabledKeys(keysToBeDisabled);
         });
+        UserEndpoint.canCurrentUserManage(user.username).then((canManage) => {
+            if (!canManage) keysToBeDisabled.push("assignRole", "disableUser", "delete");
+            setDisabledKeys(keysToBeDisabled);
+        });
     }, []);
 
     useEffect(() => {
         setDropdownItems(getDropdownItems());
     }, [userEnabled]);
 
-    function canUserBeDeleted(): Boolean {
-        // User should not be able to delete himself through this menu (can be done via "My profile")
-        if (auth.state.user?.username === user.username) return false;
-
-        // User should not be able to delete the SUPERADMIN
-        if (user.roles?.includes(Role.SUPERADMIN)) return false;
-
-        // Superadmins can delete anyone excluding themselves (and other superadmins if there are any)
-        if (auth.state.user?.roles?.includes(Role.SUPERADMIN)) return true;
-
-        // Admins should be only allowed to delete other users, not other admins
-        return !user.roles?.includes(Role.ADMIN);
-    }
-
     async function resetPassword() {
         let token = await PasswordResetEndpoint.createPasswordResetTokenForUser(user.username);
         if (token === undefined) return;
@@ -62,37 +51,53 @@ export function UserManagementCard({user}: { user: UserInfoDto }) {
     function getDropdownItems() {
         let items = [];
 
-        if (!user.enabled) {
+        if (!user.managedBySso) {
+            if (!userEnabled) {
+                items.push(
+                    {
+                        key: "enableUser",
+                        onPress: () => {
+                            UserEndpoint.setUserEnabled(user.username, true).then(() => {
+                                setUserEnabled(true);
+                            })
+                        },
+                        label: "Enable user"
+                    }
+                );
+            } else {
+                items.push(
+                    {
+                        key: "disableUser",
+                        onPress: () => {
+                            UserEndpoint.setUserEnabled(user.username, false).then(() => {
+                                setUserEnabled(false);
+                            })
+                        },
+                        label: "Disable user"
+                    }
+                );
+            }
+
             items.push(
                 {
-                    key: "enableUser",
-                    onPress: () => {
-                        RegistrationEndpoint.confirmRegistration(user.username).then(() => {
-                            setUserEnabled(true);
-                        })
-                    },
-                    label: "Enable user"
+                    key: "removeAvatar",
+                    onPress: () => AvatarEndpoint.removeAvatarByName(user.username!),
+                    label: "Remove avatar"
+                },
+                {
+                    key: "assignRole",
+                    onPress: roleAssignmentModal.onOpen,
+                    label: "Assign role"
+                },
+                {
+                    key: "resetPassword",
+                    onPress: resetPassword,
+                    label: "Reset password"
                 }
             );
         }
 
-        items.push(
-            {
-                key: "removeAvatar",
-                onPress: () => AvatarEndpoint.removeAvatarByName(user.username!),
-                label: "Remove avatar"
-            },
-            {
-                key: "assignRoles",
-                onPress: roleAssignmentModal.onOpen,
-                label: "Assign roles"
-            },
-            {
-                key: "resetPassword",
-                onPress: resetPassword,
-                label: "Reset password"
-            },
-            {
+        items.push({
                 key: "delete",
                 onPress: userDeletionConfirmationModal.onOpen,
                 label: "Delete user"
@@ -104,7 +109,8 @@ export function UserManagementCard({user}: { user: UserInfoDto }) {
 
     return (
         <>
-            <Card className={`flex flex-row justify-between p-2 ${userEnabled ? "" : "bg-warning/25"}`}>
+            <Card
+                className={`flex flex-row justify-between p-2 ${userEnabled ? "" : "bg-warning/25"} ${user.managedBySso ? "text-foreground/50" : ""}`}>
                 <div className="flex flex-row items-center gap-4">
                     <Avatar username={user.username}
                             name={user.username?.charAt(0)}
diff --git a/src/main/frontend/views/InvitationRegistrationView.tsx b/src/main/frontend/views/InvitationRegistrationView.tsx
index 2678a0d..7a59dd0 100644
--- a/src/main/frontend/views/InvitationRegistrationView.tsx
+++ b/src/main/frontend/views/InvitationRegistrationView.tsx
@@ -7,7 +7,8 @@ import {RegistrationEndpoint} from "Frontend/generated/endpoints";
 import React, {useEffect, useState} from "react";
 import {Warning} from "@phosphor-icons/react";
 import {toast} from "sonner";
-import TokenValidationResult from "Frontend/generated/de/grimsi/gameyfin/shared/token/TokenValidationResult";
+import UserInvitationAcceptanceResult
+    from "Frontend/generated/de/grimsi/gameyfin/users/enums/UserInvitationAcceptanceResult";
 
 export default function InvitationRegistrationView() {
     const [searchParams, setSearchParams] = useSearchParams();
@@ -23,7 +24,7 @@ export default function InvitationRegistrationView() {
         }
     }, [searchParams]);
 
-    async function register(values: any) {
+    async function register(values: any, formik: any) {
         let result = await RegistrationEndpoint.acceptInvitation(token, {
             email: email,
             username: values.username,
@@ -31,14 +32,17 @@ export default function InvitationRegistrationView() {
         });
 
         switch (result) {
-            case TokenValidationResult.VALID:
+            case UserInvitationAcceptanceResult.SUCCESS:
                 toast.success("Registration successful");
                 navigate("/", {replace: true});
                 break;
-            case TokenValidationResult.EXPIRED:
+            case UserInvitationAcceptanceResult.USERNAME_TAKEN:
+                formik.setFieldError("username", "Username is already taken");
+                break;
+            case UserInvitationAcceptanceResult.TOKEN_EXPIRED:
                 toast.error("Token is expired");
                 break;
-            case TokenValidationResult.INVALID:
+            case UserInvitationAcceptanceResult.TOKEN_INVALID:
             default:
                 toast.error("Token is invalid");
                 break
diff --git a/src/main/kotlin/de/grimsi/gameyfin/core/events/Events.kt b/src/main/kotlin/de/grimsi/gameyfin/core/events/Events.kt
index 4b4057c..7fdb782 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/core/events/Events.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/core/events/Events.kt
@@ -1,9 +1,7 @@
 package de.grimsi.gameyfin.core.events
 
 import de.grimsi.gameyfin.shared.token.Token
-import de.grimsi.gameyfin.shared.token.TokenType.EmailConfirmation
-import de.grimsi.gameyfin.shared.token.TokenType.Invitation
-import de.grimsi.gameyfin.shared.token.TokenType.PasswordReset
+import de.grimsi.gameyfin.shared.token.TokenType.*
 import de.grimsi.gameyfin.users.entities.User
 import org.springframework.context.ApplicationEvent
 
@@ -12,7 +10,7 @@ class UserInvitationEvent(source: Any, val token: Token<Invitation>, val baseUrl
 
 class UserRegistrationWaitingForApprovalEvent(source: Any, val newUser: User) : ApplicationEvent(source)
 
-class UserRegistrationEvent(source: Any, val newUser: User, val baseUrl: String) : ApplicationEvent(source)
+class AccountStatusChangedEvent(source: Any, val user: User, val baseUrl: String) : ApplicationEvent(source)
 
 class EmailNeedsConfirmationEvent(source: Any, val token: Token<EmailConfirmation>, val baseUrl: String) :
     ApplicationEvent(source)
@@ -23,6 +21,8 @@ class RegistrationAttemptWithExistingEmailEvent(source: Any, val existingUser: U
 class PasswordResetRequestEvent(source: Any, val token: Token<PasswordReset>, val baseUrl: String) :
     ApplicationEvent(source)
 
+class AccountDeletedEvent(source: Any, val user: User, val baseUrl: String) : ApplicationEvent(source)
+
 class GameRequestEvent(source: Any) : ApplicationEvent(source)
 
 class GameRequestApprovalEvent(source: Any) : ApplicationEvent(source)
\ No newline at end of file
diff --git a/src/main/kotlin/de/grimsi/gameyfin/core/security/SsoEnabledCondition.kt b/src/main/kotlin/de/grimsi/gameyfin/core/security/SsoEnabledCondition.kt
index 23c820b..6e88a42 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/core/security/SsoEnabledCondition.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/core/security/SsoEnabledCondition.kt
@@ -26,7 +26,8 @@ class SsoEnabledCondition : Condition {
                 statement.setString(1, ConfigProperties.SSO.OIDC.Enabled.key)
                 val resultSet = statement.executeQuery()
                 if (resultSet.next()) {
-                    return resultSet.getBoolean("value")
+                    val encryptedValue = resultSet.getString("value")
+                    return EncryptionUtils.decrypt(encryptedValue).toBoolean()
                 }
             }
         } catch (_: Exception) {
diff --git a/src/main/kotlin/de/grimsi/gameyfin/messages/MessageService.kt b/src/main/kotlin/de/grimsi/gameyfin/messages/MessageService.kt
index 07b24ca..21576fe 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/messages/MessageService.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/messages/MessageService.kt
@@ -33,9 +33,9 @@ class MessageService(
         get() = applicationContext.getBeansOfType(AbstractMessageProvider::class.java).values.toList()
 
     fun testCredentials(provider: String, credentials: Map<String, Any>): Boolean {
-        val notificationProvider = providers.find { it.providerKey == provider }
+        val messageProvider = providers.find { it.providerKey == provider }
         val credentialsProperties = Properties().apply { putAll(credentials) }
-        return notificationProvider?.testCredentials(credentialsProperties)
+        return messageProvider?.testCredentials(credentialsProperties)
             ?: throw IllegalArgumentException("Provider '$provider' not found")
     }
 
@@ -52,13 +52,13 @@ class MessageService(
     }
 
     /**
-     * Sends a test notification.
+     * Sends a test message.
      * Recipient is always the current user to prevent misuse.
      */
     fun sendTestNotification(templateKey: String, placeholders: Map<String, String>): Boolean {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send test message" }
+            log.error { "No message provider available, can't send test message" }
             return false
         }
 
@@ -68,7 +68,7 @@ class MessageService(
             val template = templateService.getMessageTemplate(templateKey)
             sendNotification(user.email, "[Gameyfin] Test Notification", template, placeholders)
         } catch (e: Exception) {
-            log.error(e) { "Failed to send test notification" }
+            log.error(e) { "Failed to send test message" }
             return false
         }
 
@@ -80,11 +80,11 @@ class MessageService(
     fun onPasswordResetRequest(event: PasswordResetRequestEvent) {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send password reset message" }
+            log.error { "No message provider available, can't send password reset message" }
             return
         }
 
-        log.info { "Sending password reset request notification" }
+        log.info { "Sending password reset request message" }
 
         val token = event.token
         val resetLink = event.baseUrl + "/reset-password?token=${token.secret}"
@@ -101,11 +101,11 @@ class MessageService(
     fun onUserRegistrationWaitingForApproval(event: UserRegistrationWaitingForApprovalEvent) {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send 'waiting for approval' message" }
+            log.error { "No message provider available, can't send 'waiting for approval' message" }
             return
         }
 
-        log.info { "Sending waiting for approval notification" }
+        log.info { "Sending waiting for approval message" }
 
         val user = event.newUser
         sendNotification(
@@ -117,23 +117,33 @@ class MessageService(
     }
 
     @Async
-    @EventListener(UserRegistrationEvent::class)
-    fun onUserRegistration(event: UserRegistrationEvent) {
+    @EventListener(AccountStatusChangedEvent::class)
+    fun onAccountStatusChanged(event: AccountStatusChangedEvent) {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send registration message" }
+            log.error { "No message provider available, can't send registration message" }
             return
         }
 
-        log.info { "Sending registration notification" }
+        log.info { "Sending registration message" }
 
-        val user = event.newUser
-        sendNotification(
-            user.email,
-            "[Gameyfin] Welcome",
-            MessageTemplates.Welcome,
-            mapOf("username" to user.username, "baseUrl" to event.baseUrl)
-        )
+        val user = event.user
+
+        if (event.user.enabled) {
+            sendNotification(
+                user.email,
+                "[Gameyfin] Your account has been enabled",
+                MessageTemplates.AccountEnabled,
+                mapOf("username" to user.username, "baseUrl" to event.baseUrl)
+            )
+        } else {
+            sendNotification(
+                user.email,
+                "[Gameyfin] Your account has been disabled",
+                MessageTemplates.AccountDisabled,
+                mapOf("username" to user.username, "baseUrl" to event.baseUrl)
+            )
+        }
     }
 
     @Async
@@ -141,11 +151,11 @@ class MessageService(
     fun onRegistrationAttemptWithExistingEmail(event: RegistrationAttemptWithExistingEmailEvent) {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send 'registration attempt with existing email' message" }
+            log.error { "No message provider available, can't send 'registration attempt with existing email' message" }
             return
         }
 
-        log.info { "Sending registration attempt with existing email notification" }
+        log.info { "Sending registration attempt with existing email message" }
 
         val user = event.existingUser
         sendNotification(
@@ -161,11 +171,11 @@ class MessageService(
     fun onEmailNeedsConfirmation(event: EmailNeedsConfirmationEvent) {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send email confirmation message" }
+            log.error { "No message provider available, can't send email confirmation message" }
             return
         }
 
-        log.info { "Sending email confirmation notification" }
+        log.info { "Sending email confirmation message" }
 
         val user = event.token.creator
         val confirmationLink = event.baseUrl + "/confirm-email?token=${event.token.secret}"
@@ -182,11 +192,11 @@ class MessageService(
     fun onUserInvitation(event: UserInvitationEvent) {
 
         if (!enabled) {
-            log.error { "No notification provider available, can't send invitation message" }
+            log.error { "No message provider available, can't send invitation message" }
             return
         }
 
-        log.info { "Sending invitation notification" }
+        log.info { "Sending invitation message" }
 
         val invitationLink = event.baseUrl + "/accept-invitation?token=${event.token.secret}"
         sendNotification(
@@ -196,4 +206,23 @@ class MessageService(
             mapOf("invitationLink" to invitationLink)
         )
     }
+
+    @Async
+    @EventListener(AccountDeletedEvent::class)
+    fun onAccountDeletion(event: AccountDeletedEvent) {
+
+        if (!enabled) {
+            log.error { "No message provider available, can't send account deletion message" }
+            return
+        }
+
+        log.info { "Sending account deletion message" }
+
+        sendNotification(
+            event.user.email,
+            "[Gameyfin] Your account has been deleted",
+            MessageTemplates.AccountDeleted,
+            mapOf("username" to event.user.username, "baseUrl" to event.baseUrl)
+        )
+    }
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/grimsi/gameyfin/messages/templates/MessageTemplates.kt b/src/main/kotlin/de/grimsi/gameyfin/messages/templates/MessageTemplates.kt
index 7db7ba6..336d238 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/messages/templates/MessageTemplates.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/messages/templates/MessageTemplates.kt
@@ -20,10 +20,24 @@ sealed class MessageTemplates(
         listOf("username")
     )
 
-    data object Welcome : MessageTemplates(
-        "welcome",
-        "Welcome",
-        "Template for the welcome message for new users",
+    data object AccountEnabled : MessageTemplates(
+        "account-enabled",
+        "Account Enabled",
+        "Template for the enabling of a users account",
+        listOf("username", "baseUrl")
+    )
+
+    data object AccountDisabled : MessageTemplates(
+        "account-disabled",
+        "Account Disabled",
+        "Template for the disabling of a users account",
+        listOf("username", "baseUrl")
+    )
+
+    data object AccountDeleted : MessageTemplates(
+        "account-deleted",
+        "Account Deleted",
+        "Template for the account deletion message",
         listOf("username", "baseUrl")
     )
 
diff --git a/src/main/kotlin/de/grimsi/gameyfin/users/UserEndpoint.kt b/src/main/kotlin/de/grimsi/gameyfin/users/UserEndpoint.kt
index c9f6e5a..5098e2c 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/users/UserEndpoint.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/users/UserEndpoint.kt
@@ -43,6 +43,11 @@ class UserEndpoint(
         userService.updateUser(username, updates)
     }
 
+    @RolesAllowed(Role.Names.ADMIN)
+    fun setUserEnabled(username: String, enabled: Boolean) {
+        userService.setUserEnabled(username, enabled)
+    }
+
     @PermitAll
     fun deleteUser() {
         val auth: Authentication = SecurityContextHolder.getContext().authentication
@@ -65,6 +70,11 @@ class UserEndpoint(
         return roleService.getRolesBelowAuth(auth).map { it.roleName }
     }
 
+    @RolesAllowed(Role.Names.ADMIN)
+    fun canCurrentUserManage(username: String): Boolean {
+        return userService.canManage(username)
+    }
+
     @RolesAllowed(Role.Names.ADMIN)
     fun assignRoles(username: String, roles: List<String>): RoleAssignmentResult {
         return userService.assignRoles(username, roles)
diff --git a/src/main/kotlin/de/grimsi/gameyfin/users/UserService.kt b/src/main/kotlin/de/grimsi/gameyfin/users/UserService.kt
index bc574c8..ec9a6d9 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/users/UserService.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/users/UserService.kt
@@ -4,10 +4,7 @@ import de.grimsi.gameyfin.config.ConfigProperties
 import de.grimsi.gameyfin.config.ConfigService
 import de.grimsi.gameyfin.core.Role
 import de.grimsi.gameyfin.core.Utils
-import de.grimsi.gameyfin.core.events.EmailNeedsConfirmationEvent
-import de.grimsi.gameyfin.core.events.RegistrationAttemptWithExistingEmailEvent
-import de.grimsi.gameyfin.core.events.UserRegistrationEvent
-import de.grimsi.gameyfin.core.events.UserRegistrationWaitingForApprovalEvent
+import de.grimsi.gameyfin.core.events.*
 import de.grimsi.gameyfin.users.dto.UserInfoDto
 import de.grimsi.gameyfin.users.dto.UserRegistrationDto
 import de.grimsi.gameyfin.users.dto.UserUpdateDto
@@ -164,7 +161,7 @@ class UserService(
         if (adminNeedsToApprove) {
             eventPublisher.publishEvent(UserRegistrationWaitingForApprovalEvent(this, user))
         } else {
-            eventPublisher.publishEvent(UserRegistrationEvent(this, user, Utils.getBaseUrl()))
+            eventPublisher.publishEvent(AccountStatusChangedEvent(this, user, Utils.getBaseUrl()))
         }
 
         if (!user.emailConfirmed) {
@@ -183,6 +180,10 @@ class UserService(
             roles = setOf(Role.USER)
         )
 
+        if (existsByUsername(user.username)) {
+            throw IllegalStateException("User with username '${user.username}' already exists")
+        }
+
         return userRepository.save(user)
     }
 
@@ -211,27 +212,22 @@ class UserService(
         userRepository.save(user)
     }
 
-    fun confirmRegistration(username: String) {
-        val user = userByUsername(username)
-        user.enabled = true
-        userRepository.save(user)
-        eventPublisher.publishEvent(UserRegistrationEvent(this, user, Utils.getBaseUrl()))
-    }
-
     fun assignRoles(username: String, roleNames: List<String>): RoleAssignmentResult {
+        if (roleNames.isEmpty()) {
+            return RoleAssignmentResult.NO_ROLES_PROVIDED
+        }
+
         val currentUser = SecurityContextHolder.getContext().authentication
         val targetUser = userByUsername(username)
 
-        val currentUserLevel = roleService.getHighestRoleFromAuthorities(currentUser.authorities).powerLevel
-        val targetUserLevel = roleService.getHighestRole(targetUser.roles).powerLevel
-
-        if (currentUserLevel <= targetUserLevel) {
+        if (!canManage(targetUser)) {
             log.error { "User ${currentUser.name} tried to assign roles to user with higher or equal power level to their own" }
             return RoleAssignmentResult.TARGET_POWER_LEVEL_TOO_HIGH
         }
 
         val newAssignedRoles = roleNames.mapNotNull { r -> Role.safeValueOf(r) }
         val newAssignedRolesLevel = roleService.getHighestRole(newAssignedRoles).powerLevel
+        val currentUserLevel = roleService.getHighestRoleFromAuthorities(currentUser.authorities).powerLevel
 
         if (currentUserLevel <= newAssignedRolesLevel) {
             log.error { "User ${currentUser.name} tried to assign roles with higher or equal power level than their own" }
@@ -243,9 +239,29 @@ class UserService(
         return RoleAssignmentResult.SUCCESS
     }
 
+    fun canManage(targetUsername: String): Boolean {
+        val targetUser = userByUsername(targetUsername)
+        return canManage(targetUser)
+    }
+
+    fun canManage(targetUser: User): Boolean {
+        val currentUser = SecurityContextHolder.getContext().authentication
+        val currentUserLevel = roleService.getHighestRoleFromAuthorities(currentUser.authorities).powerLevel
+        val targetUserLevel = roleService.getHighestRole(targetUser.roles).powerLevel
+        return currentUserLevel > targetUserLevel
+    }
+
+    fun setUserEnabled(username: String, enabled: Boolean) {
+        val user = userByUsername(username)
+        user.enabled = enabled
+        userRepository.save(user)
+        eventPublisher.publishEvent(AccountStatusChangedEvent(this, user, Utils.getBaseUrl()))
+    }
+
     fun deleteUser(username: String) {
         val user = userByUsername(username)
         userRepository.delete(user)
+        eventPublisher.publishEvent(AccountDeletedEvent(this, user, Utils.getBaseUrl()))
     }
 
     fun toUserInfo(user: User): UserInfoDto {
diff --git a/src/main/kotlin/de/grimsi/gameyfin/users/enums/RoleAssignmentResult.kt b/src/main/kotlin/de/grimsi/gameyfin/users/enums/RoleAssignmentResult.kt
index 3ec2984..517795f 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/users/enums/RoleAssignmentResult.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/users/enums/RoleAssignmentResult.kt
@@ -2,6 +2,7 @@ package de.grimsi.gameyfin.users.enums
 
 enum class RoleAssignmentResult {
     SUCCESS,
+    NO_ROLES_PROVIDED,
     TARGET_POWER_LEVEL_TOO_HIGH,
     ASSIGNED_ROLE_POWER_LEVEL_TOO_HIGH
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/grimsi/gameyfin/users/enums/UserInvitationAcceptanceResult.kt b/src/main/kotlin/de/grimsi/gameyfin/users/enums/UserInvitationAcceptanceResult.kt
new file mode 100644
index 0000000..298f96f
--- /dev/null
+++ b/src/main/kotlin/de/grimsi/gameyfin/users/enums/UserInvitationAcceptanceResult.kt
@@ -0,0 +1,8 @@
+package de.grimsi.gameyfin.users.enums
+
+enum class UserInvitationAcceptanceResult {
+    SUCCESS,
+    TOKEN_INVALID,
+    TOKEN_EXPIRED,
+    USERNAME_TAKEN
+}
\ No newline at end of file
diff --git a/src/main/kotlin/de/grimsi/gameyfin/users/registration/InvitationService.kt b/src/main/kotlin/de/grimsi/gameyfin/users/registration/InvitationService.kt
index f2be9c3..61ff3bf 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/users/registration/InvitationService.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/users/registration/InvitationService.kt
@@ -1,15 +1,15 @@
 package de.grimsi.gameyfin.users.registration
 
 import de.grimsi.gameyfin.core.Utils
+import de.grimsi.gameyfin.core.events.AccountStatusChangedEvent
 import de.grimsi.gameyfin.core.events.UserInvitationEvent
-import de.grimsi.gameyfin.core.events.UserRegistrationEvent
 import de.grimsi.gameyfin.shared.token.TokenDto
 import de.grimsi.gameyfin.shared.token.TokenRepository
 import de.grimsi.gameyfin.shared.token.TokenService
 import de.grimsi.gameyfin.shared.token.TokenType.Invitation
-import de.grimsi.gameyfin.shared.token.TokenValidationResult
 import de.grimsi.gameyfin.users.UserService
 import de.grimsi.gameyfin.users.dto.UserRegistrationDto
+import de.grimsi.gameyfin.users.enums.UserInvitationAcceptanceResult
 import org.springframework.context.ApplicationEventPublisher
 import org.springframework.security.core.Authentication
 import org.springframework.security.core.context.SecurityContextHolder
@@ -44,15 +44,19 @@ class InvitationService(
         return payload[EMAIL_KEY]
     }
 
-    fun acceptInvitation(secret: String, registration: UserRegistrationDto): TokenValidationResult {
-        val invitationToken = super.get(secret, Invitation) ?: return TokenValidationResult.INVALID
-        val email = invitationToken.payload[EMAIL_KEY] ?: return TokenValidationResult.INVALID
-        if (invitationToken.expired) return TokenValidationResult.EXPIRED
+    fun acceptInvitation(secret: String, registration: UserRegistrationDto): UserInvitationAcceptanceResult {
+        val invitationToken = super.get(secret, Invitation) ?: return UserInvitationAcceptanceResult.TOKEN_INVALID
+        val email = invitationToken.payload[EMAIL_KEY] ?: return UserInvitationAcceptanceResult.TOKEN_INVALID
+        if (invitationToken.expired) return UserInvitationAcceptanceResult.TOKEN_EXPIRED
 
-        val user = userService.registerUserFromInvitation(registration, email)
-        super.delete(invitationToken)
-        eventPublisher.publishEvent(UserRegistrationEvent(this, user, Utils.getBaseUrl()))
+        try {
+            val user = userService.registerUserFromInvitation(registration, email)
+            super.delete(invitationToken)
+            eventPublisher.publishEvent(AccountStatusChangedEvent(this, user, Utils.getBaseUrl()))
+        } catch (e: IllegalStateException) {
+            return UserInvitationAcceptanceResult.USERNAME_TAKEN
+        }
 
-        return TokenValidationResult.VALID
+        return UserInvitationAcceptanceResult.SUCCESS
     }
 }
\ No newline at end of file
diff --git a/src/main/kotlin/de/grimsi/gameyfin/users/registration/RegistrationEndpoint.kt b/src/main/kotlin/de/grimsi/gameyfin/users/registration/RegistrationEndpoint.kt
index 00c359b..115bdb4 100644
--- a/src/main/kotlin/de/grimsi/gameyfin/users/registration/RegistrationEndpoint.kt
+++ b/src/main/kotlin/de/grimsi/gameyfin/users/registration/RegistrationEndpoint.kt
@@ -4,9 +4,9 @@ import com.vaadin.flow.server.auth.AnonymousAllowed
 import com.vaadin.hilla.Endpoint
 import de.grimsi.gameyfin.core.Role
 import de.grimsi.gameyfin.shared.token.TokenDto
-import de.grimsi.gameyfin.shared.token.TokenValidationResult
 import de.grimsi.gameyfin.users.UserService
 import de.grimsi.gameyfin.users.dto.UserRegistrationDto
+import de.grimsi.gameyfin.users.enums.UserInvitationAcceptanceResult
 import jakarta.annotation.security.RolesAllowed
 
 @AnonymousAllowed
@@ -29,7 +29,7 @@ class RegistrationEndpoint(
         return !userService.existsByUsername(username)
     }
 
-    fun acceptInvitation(token: String, registration: UserRegistrationDto): TokenValidationResult {
+    fun acceptInvitation(token: String, registration: UserRegistrationDto): UserInvitationAcceptanceResult {
         return invitationService.acceptInvitation(token, registration)
     }
 
@@ -37,11 +37,6 @@ class RegistrationEndpoint(
         return invitationService.getAssociatedEmail(token)
     }
 
-    @RolesAllowed(Role.Names.ADMIN)
-    fun confirmRegistration(username: String) {
-        userService.confirmRegistration(username)
-    }
-
     @RolesAllowed(Role.Names.ADMIN)
     fun createInvitation(email: String): TokenDto {
         return invitationService.createInvitation(email)
diff --git a/src/main/resources/templates/messages/account-deleted.mjml b/src/main/resources/templates/messages/account-deleted.mjml
new file mode 100644
index 0000000..50081a7
--- /dev/null
+++ b/src/main/resources/templates/messages/account-deleted.mjml
@@ -0,0 +1,30 @@
+<mjml>
+    <mj-head>
+        <mj-title>[Gameyfin] Welcome</mj-title>
+        <mj-attributes>
+            <mj-all font-family="Arial, sans-serif"/>
+            <mj-text font-size="16px"/>
+        </mj-attributes>
+    </mj-head>
+    <mj-body>
+        <mj-section>
+            <mj-column>
+                <mj-image alt="Gameyfin Logo" title="Gameyfin Logo" width="128px" src="{logo}"/>
+                <mj-image alt="Gameyfin Logo" title="Gameyfin Logo" height="2px" padding-bottom="20px"
+                          src="{gradient}"/>
+
+                <mj-text font-size="20px" font-family="helvetica">Hello there {username},
+                    <br/>
+                    <br/>
+                </mj-text>
+                <mj-text>your account has been permanently deleted.
+                    <br/>
+                    You will be missed!
+                    <br/>
+                    If you think this is a mistake, contact your <a href="{baseUrl}">Gameyfin</a> administrator.
+                </mj-text>
+
+            </mj-column>
+        </mj-section>
+    </mj-body>
+</mjml>
\ No newline at end of file
diff --git a/src/main/resources/templates/messages/account-disabled.mjml b/src/main/resources/templates/messages/account-disabled.mjml
new file mode 100644
index 0000000..2211773
--- /dev/null
+++ b/src/main/resources/templates/messages/account-disabled.mjml
@@ -0,0 +1,28 @@
+<mjml>
+    <mj-head>
+        <mj-title>[Gameyfin] Welcome</mj-title>
+        <mj-attributes>
+            <mj-all font-family="Arial, sans-serif"/>
+            <mj-text font-size="16px"/>
+        </mj-attributes>
+    </mj-head>
+    <mj-body>
+        <mj-section>
+            <mj-column>
+                <mj-image alt="Gameyfin Logo" title="Gameyfin Logo" width="128px" src="{logo}"/>
+                <mj-image alt="Gameyfin Logo" title="Gameyfin Logo" height="2px" padding-bottom="20px"
+                          src="{gradient}"/>
+
+                <mj-text font-size="20px" font-family="helvetica">Hello there {username},
+                    <br/>
+                    <br/>
+                </mj-text>
+                <mj-text>your account has been disabled.
+                    <br/>
+                    If you think this is a mistake, contact your <a href="{baseUrl}">Gameyfin</a> administrator.
+                </mj-text>
+
+            </mj-column>
+        </mj-section>
+    </mj-body>
+</mjml>
\ No newline at end of file
diff --git a/src/main/resources/templates/messages/welcome.mjml b/src/main/resources/templates/messages/account-enabled.mjml
similarity index 93%
rename from src/main/resources/templates/messages/welcome.mjml
rename to src/main/resources/templates/messages/account-enabled.mjml
index 617aacf..3d2845a 100644
--- a/src/main/resources/templates/messages/welcome.mjml
+++ b/src/main/resources/templates/messages/account-enabled.mjml
@@ -17,7 +17,7 @@
                     <br/>
                     <br/>
                 </mj-text>
-                <mj-text>your registration has been approved!
+                <mj-text>your account has been enabled!
                     <br/>
                     You can now start browsing games in <a href="{baseUrl}">Gameyfin</a>.
                 </mj-text>