> That's how we all start. Don't worry about that. Thanks :)
On which port does your client connect? Once we have that, we can check the > config on Postfix's end. > > my client is set for port 25 and authentication mode is AUTO client is outlook. btw issue is not at client side i believe that issue is at MTA level Connection diagram is like this _______________________Network Solution Mailserver/MTA | Outlook2007 client == |________________________MY VPS MTA/Mailserver. my outlook client is set with two accounts. 1 Network Solution company's Mailserver and 2nd my own VPS Mailserver. my own VPS is seems to be working fine and can receive emails from gmail, hotmail, and yahoo. "but when Network solution mailserver/MTA" send this email to "MY VPS MTA" (which is actually generated from my own outlook client faild to send and end up with mantioned error. and on server side i only see these two lines and nothing else. Apr 5 01:27:03 FirstDebian postfix/submission/smtpd[20582]: connect from atl4mhob16.myregisteredsite.com[209.17.115.109] Apr 5 01:27:05 FirstDebian postfix/submission/smtpd[20582]: disconnect from atl4mhob16.myregisteredsite.com[209.17.115.109] Thanks, Yousuf