Telnet command works internally, but not externally RRS feed

  • Question

  • I have a new Exchange 2013 installation.  Incoming Internet mail stops periodically.  Internal works fine all the time as near as I can tell.  When incoming Internet mail stops, I noticed that I can telnet my Exchange server from within the network, but cannot outside the network.  I get a "service not available" error.  I restart the server and everything works fine - for awhile.  I have tried restarting various Exchange services when things aren't working, but nothing seems to work until I do a complete restart - I then get a normal telnet response.  I'm not seeing any red flags in the event viewer, either.  Is it possible Exchange is shutting down Internet mail only?  Thanks!
    Saturday, January 4, 2014 11:12 AM

All replies

  • Hi

    Do you have any AV or firewalls on your server? If you just restart the transport service does mail flow? does this happen at a specific time of day? Any backups running that are either freezing the Hyper-V server or hogging the resources on the box?

    Saturday, January 4, 2014 5:36 PM
  • I turned off all firewalls. 

    I have AVG antivirus on the Exchange server.  I have setup the proper excludes.  I did not install the AVG Exchange component because I have had problems with it on two other Exchange servers.  So I only installed the file server component - even though there are no file shares on the Exchange server.  I did activate the antispam/antivirus protection that comes with Exchange 2013.  The Exchange server is a Hyper V VM on Windows Server 2012 R2.  It has 10 GB of RAM allocated - I've never seen it use it all.  60 GB of free disk space on a drive total of 120 GB.  There are only 15 users.  Pretty small installation.

    I did not do a migration from their old server.  They seemed to have enough problems.  So I setup a completely new domain and Exchange server.  Recreated all the user accounts.  Transferred mail into Outlook via PST backups from their old mailbox.

    I am using a Barracuda backup device.  It backs up in the evening.  The outages have occurred during the day.

    Haven't noticed excessive resource usage, but I will look more closely.

    Restarting the Transport service has no affect.

    Saturday, January 4, 2014 7:52 PM
  • But why is it I can telnet internally, but not externally when mail stops?
    Saturday, January 4, 2014 8:10 PM
  • Update - Exchange became functional after restarting the Transport service only.  Could have sworn this didn't work previously.
    Saturday, January 4, 2014 8:38 PM
  • I'm getting these in the Event Viewer:

    Saturday, January 4, 2014 9:38 PM
  • Hello,

    It is likely that when you are connecting with telnet internally that you would be connecting to a different receive connector than internet mail would connect to. This may be why telnet works internally but fails externally. I would suggest setting the protocol logging level to verbose on the receive connector that external mail uses to see if you can get some additional information. Just keep in mind that depending on mail volume protocol logs can grow quite quickly.

    Sunday, January 5, 2014 3:32 AM
  • Hi,

    From your description, I recommend you verify the following things:

    1. All firewalls are turned off.

    2. Ports 25, 53, 80, 110, 143, 443 and 993 are forwarded to the Exchange Server.

    3. Transport Service are started.

    If the issue persists, please disable the recipient connector and then enable it.

    Hope my clarification is helpful.

    If there are any problems, please feel free to let me know.

    Best regards,

    Amy Wang
    TechNet Community Support

    Monday, January 6, 2014 1:52 PM