I have tried practically everything but pulling my hair out... which is coming up very soon. problem is as follows... clients can recieve emails, clients cant send email... when they try and send email, no matter if they have the "my outgoing requires auth...." checked on or off, the result is still the same..... result: 503 This mail server requires authentication. Please check your mail client settings some Mailenable logs show as follows. Relay Denied: Failed to meet all relay criteria. Though as stated before, the "my server requi...." is checked on correctly.... i setup the same test email on outlook express within the server and tried sending out a email.... relaying went through fine... so problem lies with incoming smtp connections are dropped.... here is a manual smtp test by telneting to the server on port 25.... 220 domain.com ESMTP MailEnable Service, Version: 1.73-- ready at 08/04/04 00:35 :47 HELO domain.com 250 Requested mail action okay, completed MAIL FROM: firstname.lastname@example.org 250 Requested mail action okay, completed RCPT TO: email@example.com 503 This mail server requires authentication. Please check your mail client settings.