We are running Exchange Server 5.5 SP4, clients are Outlook 98/2000 on Win95/98/NT/2000. We have one user, and one user only, who has constant problems sending attachments to Internet accounts from his Outlook email account. Attachments sent to local users are OK. He uses Outlook 98 on a W98 machine, he has Exchange Server client, Internet Mail, Personal Folders and Personal Address book configured in his mail profile, as does everyone else. (Mail is delivered to Mailbox but saved indefinitely in Personal Folders.) Attachments that he sends (MS Word, Excel) end up as garbage on the other end. I can send the same attachment from my computer to the same destination, and it will be fine. We rebuilt his computer, gave him a new computer, gave him a new email account, but the problem persists. I know it doesn't seem like this makes any sense at all but I thought I'd throw it out and see if anyone has any suggestions. Internet email sending format is MIME but we have also tried UUENCODE with no success.