diff --git a/src/app/directives/library-membership.directive.spec.ts b/src/app/directives/library-membership.directive.spec.ts
index e6e2b44e4..11e58ce18 100644
--- a/src/app/directives/library-membership.directive.spec.ts
+++ b/src/app/directives/library-membership.directive.spec.ts
@@ -179,5 +179,35 @@ describe('LibraryMembershipDirective', () => {
       tick();
       expect(directive.error.emit).toHaveBeenCalled();
     }));
+
+    it('should emit specific error message on invalid email address server error', fakeAsync(() => {
+      const emitErrorSpy = spyOn(directive.error, 'emit');
+      const selection = { entry: { id: 'no-membership-requested' } };
+      const change = new SimpleChange(null, selection, true);
+      directive.ngOnChanges({ selection: change });
+      tick();
+
+      const testData = [
+        {
+          fixture: 'Failed to resolve sender mail address',
+          expected: 'APP.MESSAGES.ERRORS.INVALID_SENDER_EMAIL'
+        },
+        {
+          fixture: 'All recipients for the mail action were invalid',
+          expected: 'APP.MESSAGES.ERRORS.INVALID_RECEIVER_EMAIL'
+        }
+      ];
+
+      testData.forEach(data => {
+        addMembershipSpy.and.returnValue(throwError({ message: data.fixture }));
+        emitErrorSpy.calls.reset();
+        directive.toggleMembershipRequest();
+        tick();
+        expect(emitErrorSpy).toHaveBeenCalledWith({
+          error: { message: data.fixture },
+          i18nKey: data.expected
+        });
+      });
+    }));
   });
 });
diff --git a/src/app/directives/library-membership.directive.ts b/src/app/directives/library-membership.directive.ts
index fda7569f2..8eb3e2b5f 100644
--- a/src/app/directives/library-membership.directive.ts
+++ b/src/app/directives/library-membership.directive.ts
@@ -134,12 +134,15 @@ export class LibraryMembershipDirective implements OnChanges {
           const senderEmailCheck = 'Failed to resolve sender mail address';
           const receiverEmailCheck =
             'All recipients for the mail action were invalid';
-          if (
-            error.message &&
-            (error.message.includes(senderEmailCheck) ||
-              error.message.includes(receiverEmailCheck))
-          ) {
-            errWithMessage.i18nKey = 'APP.MESSAGES.ERRORS.INVALID_EMAIL';
+
+          if (error.message) {
+            if (error.message.includes(senderEmailCheck)) {
+              errWithMessage.i18nKey =
+                'APP.MESSAGES.ERRORS.INVALID_SENDER_EMAIL';
+            } else if (error.message.includes(receiverEmailCheck)) {
+              errWithMessage.i18nKey =
+                'APP.MESSAGES.ERRORS.INVALID_RECEIVER_EMAIL';
+            }
           }
 
           this.error.emit(errWithMessage);
diff --git a/src/assets/i18n/en.json b/src/assets/i18n/en.json
index 3aa3db4fb..b916f3fc5 100644
--- a/src/assets/i18n/en.json
+++ b/src/assets/i18n/en.json
@@ -278,7 +278,8 @@
                 "JOIN_REQUEST_FAILED": "Cannot join the library",
                 "JOIN_CANCEL_FAILED": "Cannot cancel the request to join the library",
                 "LEAVE_LIBRARY_FAILED": "Cannot leave this library",
-                "INVALID_EMAIL": "Sender or receiver email configured on server not valid, contact IT"
+                "INVALID_SENDER_EMAIL": "Your email address must be valid before requesting to join.",
+                "INVALID_RECEIVER_EMAIL": "Recipient(s) email address not valid, contact IT."
             },
             "UPLOAD": {
                 "ERROR": {