diff --git a/NEWS b/NEWS
index 3fe6c1638..5abe82a84 100644
--- a/NEWS
+++ b/NEWS
@@ -6,6 +6,7 @@ New features
 
 Bug fixes
  - [web] use the organizer's alarm by default when accepting IMIP messages (#3934)
+ - [web] fixed forwarding mails with attachments containing slashes in file names
  - [eas] don't include task folders if we hide them in SOGo (#4164)
  - [core] not using cleaned data when sending mails (#4199)
  - [core] don't update subscriptions when owner is not the active user (#3988)
diff --git a/SoObjects/Mailer/SOGoDraftObject.m b/SoObjects/Mailer/SOGoDraftObject.m
index 1b21ff364..7bd3565fd 100644
--- a/SoObjects/Mailer/SOGoDraftObject.m
+++ b/SoObjects/Mailer/SOGoDraftObject.m
@@ -1158,7 +1158,14 @@ static NSString    *userAgent      = nil;
     name = [name substringFromIndex: r.location + 1];
 
   if (![self isValidAttachmentName: name])
-    return [self invalidAttachmentNameError: name];
+    {
+      if ([name rangeOfString: @"/"].length)
+        {
+          name = [name stringByReplacingOccurrencesOfString: @"/"  withString: @"-"];
+        }
+      else
+        return [self invalidAttachmentNameError: name];
+    }
   
   p = [self pathToAttachmentWithName: name];
   if (![_attach writeToFile: p atomically: YES])