diff --git a/models/mail.model b/models/mail.model
index b24420e74..a9a3209d1 100644
--- a/models/mail.model
+++ b/models/mail.model
@@ -3,7 +3,7 @@ SentMail
     sentBy       InstanceId
     objectId     MailObjectId Maybe
     bounceSecret BounceSecret Maybe
-    recipient    UserId Maybe
+    recipient    UserId Maybe OnDeleteCascade
     headers      MailHeaders
     contentRef   SentMailContentId
     deriving Generic