How do I get my users outbound emails to work?

On June 10 all was well, but beginning June 11 we were able to receive emails, but was unable to send.I am getting a variety of error message as the emails bounce back. The Queues has emails there with an additional information such as:

Remote server did not respond to a connection attempt
Unable to bind to destination server in DNS
An SMTP protocol error has occured

We are using Microsoft Windows Server 2003 Standard with Exchange Server 2003 Standard and we are behind SonicWall Pro 1260 Standard. Nothing was changed between June 10 and June 11 when the problem began. Begining June 11, our outbound emails started to bounce back to us with different error messages such as:

  Could not deliver the message in the time limit specified.  Please retry or contact your administrator. <Exchange Server Name #4.4.7>

  There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator. <Exchange server's name ##5.5.0 smtp;554 delivery error: dd This user doesn't have an account> (but they do have an account becuase email went eariler this month)

Delivery to the following recipients has been delayed. (then a few days later with one of the above errors>

Has anyone experience this problem. I have very thoroughly check the exchange server, but could not find anything wrong.
bayviewbcAsked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
itmonitorConnect With a Mentor Commented:
We had 3 similar issues. 1)our forwarder to our outside domain name crashed/couldn't relay the messages appropriately.  I had to call the ISP to get a new DNS forwarder IP address to get the messages working.  2) we were blacklisted by accident and the website I used to block all blacklisted transmissions also blocked all outgoing messages.  3) we made a patch to the exchange server (it was an OS patch) and for some reason it starting destroying dns requests.  We had to remove the patch to get it to work.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.