Question : Mail not received from some senders

Hello,

I have a client running SBS 2003 SP2 w/ Exchange SP2 behind a Firebox X10e.

The client cannot receive email from some sending domains; most others work fine. One sender received a bounce back as follows:

Your message

  To:      [email protected]
  Subject: Test
  Sent:    Thu, 21 Aug 2008 10:04:00 -0400

did not reach the following recipient(s):

[email protected] on Thu, 21 Aug 2008 10:07:12 -0400
    There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
    - psmtp>

When I use MXToolbox.com to run a test on the mail server, everything look good except for a transaction time of 5.438 seconds, which triggers a warning. I am not sure if this is related, but I feel it could be.

Also, I tested sending email from four email accounts from various domains. Three worked, but mail sent from Gmail does not.

Has anyone experienced this problem before, or does anyone have suggestions for what I might try? I will greatly appreciate any help in this matter.

Thanks!

Answer : Mail not received from some senders

It means that the Mail Transfer Agent timed out on the message. I'm guessing its on your end but can't be sure without further checking. the transaction time isn't too bad.

I'd turn on message tracking and check the event logs, if you could past that here along the domain you manage and some of the ones the error happens with

Any more information on the setup would be good also, firewall type, ISP, are you using a smarthost etc.