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Slow SMTP connections, delay after HELO

Discussion in 'E-mail Discussions' started by bcrooker, Jun 4, 2013.

  1. bcrooker

    bcrooker Member

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    We just migrated to cPanel from Plesk, and we are having some email related issues. One is the speed in which SMTP transactions are occuring. They are very slow, to the point of timing out for Gmail and a few other things. I have narrowed it down to a delay between the sending of a HELO command and the display of the banner.

    So if I do:

    telnet myserver.com 25

    and then when it connects, I type

    helo mydomain.com

    It waits 15 seconds before showing the banner. I turned on all logging for Exim, and I get something like this:

    2013-06-03 19:53:31 [2836] SMTP connection from [nnn.nnn.nnn.nnn]:35665 I=[mmm.mmm.mmm.mmm]:25 (TCP/IP connection count = 2)
    2013-06-03 19:53:46 [2939] list matching forced to fail: failed to find host name for nnn.nnn.nnn.nnn
    2013-06-03 19:53:46 [2939] list matching forced to fail: failed to find host name for nnn.nnn.nnn.nnn
    2013-06-03 19:53:49 [2939] SMTP connection from (mydomain.com) [nnn.nnn.nnn.nnn]:35665 I=[mmm.mmm.mmm.mmm]:25 closed by QUIT
    2013-06-03 19:53:49 [2939] no MAIL in SMTP connection from (crookers.com) [nnn.nnn.nnn.nnn]:35665 I=[mmm.mmm.mmm.mmm]:25 D=18s
    C=HELO,QUIT

    You can see the 15 second delay between the first and second lines. I have found other logs files that people have posted for related issue, but the delay they are seeing between the first and second lines is much smaller, like 1 second or a few seconds.

    Yes, we have the rfc1413 ident stuff turned off (timeout set to 0s)
     
    #1 bcrooker, Jun 4, 2013
    Last edited: Jun 4, 2013
  2. bcrooker

    bcrooker Member

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    Fixed. Problem turned out to be an invalid IP address in the resolv file
     
  3. cPanelMichael

    cPanelMichael Forums Analyst
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    Thank you for taking the time to let us know you resolved the issue by updating the /etc/resolv.conf file with valid resolvers. I am marking this thread as [Resolved].
     
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