Since upgrading to 7.5.3 (Linux), I have lost all ability to send email from Outlook using SMTP. I've tested it on two different machines with the same problem on each. I am able to send SMTP email through Netscape, and my webmail is working fine. I've read through all of the posts that deal with this issue, and the only solution that I see is on a windows-based machine where people have set up an open relay for limited IP addresses. This doesn't appear to be an option in Linux. It's either completely open or not. Has anyone found a solution? Clients are not too happy right now. Thank you.