Hello, This problem has been keeping me busy for quite a while now, and I can't think of any other options or tests. The situation : ISA server connected to the ISP through DSL. Everything works well, including webaccess through the proxy, and other access by using the Firewall Client. I have set up a bunch of rules to make things work and it all makes sense it seems. However, there's an email problem. We don't have an internal e-mail server, so all mail is going straight to the ISP, through ISA. When I send a normal mail (like this one) it works without problems. However, when I send a mail with an attachement, nothing happens and the mail will not be sent. I have no SMTP filters running (disabled the standard one so it's not interfering), and all traffic is allowed including SMTP traffic (as shown by the succesful sending of mails without attachments). Does anyone have an idea why my attachements are not getting sent at all? The ISP is not the problem, because I have no problems when I connect using a dial-up connection on my local computer. ISA seems to refuse my mails with attachements but I have no idea why or where it's told to do so! Thanks in advance, Marc Aarts