I have an SSRS server that processes many subscriptions on a daily basis. I have just become aware of this, so I don't know if it is a new or an old problem, but only one subscription has been failing on a daily basis. The error is:

Failure sending mail: Service not available, closing transmission channel. The server response was: 4.4.1 Connection timed out

A quick Google search has indicated that this is a response by the Exchange server. I am not sure how to begin troubleshooting this. I do not have access to the Exchange server. If I was going to punt this to the Exchange team, I would want to be able to back up why I think they need to troubleshoot. The problem is many other subscriptions are processed just fine with email sent. Can the processing time for the report affect the email process? I don't think so because the report is processed and rendered prior to trying to email. Please let me know how you recommend I proceed with troubleshooting?

1 Answer 1


Your Exchange Team should be able (with the time & date when the error message happen) say for sure what happened here. Out of the blue the following might happened:

  • The Exchange throttling policy blocked your construct from sending emails. This could happen if you are hammering the exchange server with to much emails.
  • There was a expected maintenance (e.g. Installation Windows updated, ...) on the Exchange server.
  • An Antivirus Solution temporary blocked the access (on your environment or on Exchange). You might wish to check the logfiles from the antivirus solution here if you see something in them which is related.
  • An AntiSpam Solution temporary blocked your access
  • A network issue between your server and the Exchange server (this might be something to check if there isn´t anything found on the Exchange or your side)

And normally the time the process to handle the email should not cause such issues as the server should re-open the session if needed. However a bug might prevent that (so if none of the solutions above would lead into a good direction I would check if everything is up to date). Your Exchange team could also allow a longer "online" session and prevent a to fast disconnect (if they wish and think this is useful). But they should be also be able to see that in the log files.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .