The message arrives but sometimes the attachment is missing. Everything works fine with internal users. They are getting all his attachments. When I send attachments to may own external email addresses from this users mailbox I get them no problem. It just seems to be some external recipients who are not recieving the attachments they are not any particular group, however if I send the same email from my mailbox (on the same network) these same recipients get the attachment OK. Could it be perhaps a 'blacklist' type setting to remove attachments from this particular sender? It is the ony thing I can think of, but normally you would expect that to block the message altogether?