diff --git a/jslib b/jslib
index 28d21ca5..7f6d7424 160000
--- a/jslib
+++ b/jslib
@@ -1 +1 @@
-Subproject commit 28d21ca5dfacd1487cd92345d8be9554079fbd96
+Subproject commit 7f6d7424e77bccd68b63506b1205ef0dfa7c21bd
diff --git a/src/app/tabs/settings.component.html b/src/app/tabs/settings.component.html
index fb3b3edc..8f9b8e87 100644
--- a/src/app/tabs/settings.component.html
+++ b/src/app/tabs/settings.component.html
@@ -271,7 +271,8 @@
                             <small class="text-muted form-text">{{'ex' | i18n}} whenChanged</small>
                         </div>
                     </div>
-
+                </div>
+                <div [hidden]="directory != directoryType.Ldap && directory != directoryType.OneLogin">
                     <div class="form-group">
                         <div class="form-check">
                             <input class="form-check-input" type="checkbox" id="useEmailPrefixSuffix"
@@ -281,7 +282,7 @@
                         </div>
                     </div>
                     <div [hidden]="!sync.useEmailPrefixSuffix">
-                        <div class="form-group" [hidden]="ldap.ad">
+                        <div class="form-group" [hidden]="ldap.ad || directory != directoryType.Ldap">
                             <label for="emailPrefixAttribute">{{'emailPrefixAttribute' | i18n}}</label>
                             <input type="text" class="form-control" id="emailPrefixAttribute"
                                 name="EmailPrefixAttribute" [(ngModel)]="sync.emailPrefixAttribute">
diff --git a/src/services/onelogin-directory.service.ts b/src/services/onelogin-directory.service.ts
index 484ef140..3977c028 100644
--- a/src/services/onelogin-directory.service.ts
+++ b/src/services/onelogin-directory.service.ts
@@ -12,6 +12,9 @@ import { DirectoryService } from './directory.service';
 import { I18nService } from 'jslib/abstractions/i18n.service';
 import { LogService } from 'jslib/abstractions/log.service';
 
+// Basic email validation: something@something.something
+const ValidEmailRegex = /^\S+@\S+\.\S+$/;
+
 export class OneLoginDirectoryService extends BaseDirectoryService implements DirectoryService {
     private dirConfig: OneLoginConfiguration;
     private syncConfig: SyncConfiguration;
@@ -82,9 +85,23 @@ export class OneLoginDirectoryService extends BaseDirectoryService implements Di
         const entry = new UserEntry();
         entry.externalId = user.id;
         entry.referenceId = user.id;
-        entry.email = user.email != null ? user.email.trim().toLowerCase() : null;
         entry.deleted = false;
         entry.disabled = user.status === 2;
+        entry.email = user.email;
+        const emailInvalid = (ue: UserEntry) => ue.email == null || ue.email === '';
+        if (emailInvalid(entry) && user.username != null && user.username !== '') {
+            if (this.validEmailAddress(user.username)) {
+                entry.email = user.username;
+            } else if (this.syncConfig.useEmailPrefixSuffix && this.syncConfig.emailSuffix != null) {
+                entry.email = user.username + this.syncConfig.emailSuffix;
+            }
+        }
+        if (entry.email != null) {
+            entry.email = entry.email.trim().toLowerCase();
+        }
+        if (emailInvalid(entry) || !this.validEmailAddress(entry.email)) {
+            return null;
+        }
         return entry;
     }
 
@@ -173,4 +190,8 @@ export class OneLoginDirectoryService extends BaseDirectoryService implements Di
         }
         return this.apiGetMany(response.pagination.next_link, currentData);
     }
+
+    private validEmailAddress(email: string) {
+        return ValidEmailRegex.test(email);
+    }
 }