diff --git a/src/main/java/org/olat/core/util/mail/manager/MailManagerImpl.java b/src/main/java/org/olat/core/util/mail/manager/MailManagerImpl.java
index 1c255d0096bcb0ef2b735dee5555944306125b85..b90b058a2caa976fb89d3dedad22a71f0528950f 100644
--- a/src/main/java/org/olat/core/util/mail/manager/MailManagerImpl.java
+++ b/src/main/java/org/olat/core/util/mail/manager/MailManagerImpl.java
@@ -426,6 +426,7 @@ public class MailManagerImpl extends BasicManager implements MailManager {
 	 */
 	@Override
 	public void delete(DBMailLight mail, Identity identity, boolean deleteMetaMail) {
+		if(mail == null) return;//already deleted
 		if(StringHelper.containsNonWhitespace(mail.getMetaId()) && deleteMetaMail) {
 			List<DBMailLight> mails = getEmailsByMetaId(mail.getMetaId());
 			for(DBMailLight childMail:mails) {