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Trouble with Remote Mail Exchanger and Mail Delivery

Comments

8 comments

  • cPanelMichael
    Hello :) Could you let us know the specific entry in /var/log/exim_mainlog when this happens? EX:
    exigrep user@domain /var/log/exim_mainlog
    Thank you.
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  • dreohio99
    Hello :) Could you let us know the specific entry in /var/log/exim_mainlog when this happens? EX:
    exigrep user@domain /var/log/exim_mainlog
    Thank you.

    Is there something specific I should be looking for? Is there somewhere private I can send the log entry or should I just modify all references to IPs, e-mails, and domains?
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  • cPanelMichael
    You are looking for the specific error message when the delivery attempt fails. You can post it here in CODE tags as long as you remove any identifying information about the domain name or server. Thank you.
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  • alphawolf50
    I have more information regarding this issue (OP and I know each other). The issue is that Exim is sending mail from the wrong IP address under certain conditions, and an SPF record for the sending domain ending in "-all" will cause some hosts to reject the email. I've not systematically tested each condition to see which triggers this behavior, but these are the conditions that seem to be the logical causes:
      ]
    • Exim configured to "Send mail from account"s dedicated IP address"
    • Sending account has dedicated IP address on server. (x.x.x.100)
    • Sending account uses local mail exchanger.
    • Receiving account is a reseller account with a "reseller's shared IP" (x.x.x.200)
    • Receiving account uses a remote mail exchanger.
    In this case, the sending email exits the server from x.x.x.200, instead of x.x.x100. The receiving MTA checks sender's SPF and sees that x.x.x.200 is not an authorized sender, and rejects the mail. I was able to confirm this behavior by viewing the headers on an email sent to another account with the exact same setup, but where the receiving MTA was not strict about SPF. Relevant (redacted) Exim logs for the failed email is below:
    2016-03-23 22:09:23 1aiuiA-0007x0-Kz SMTP connection outbound 1458785363 1aiuiA-0007x0-Kz .com user@.com 2016-03-23 22:09:26 1aiuiA-0007x0-Kz ** user@.com R=dkim_lookuphost T=dkim_remote_smtp H=xxxxxxx.xxx.barracudanetworks.com [x.x.x.x] X=TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256 CV=yes: SMTP error from remote mail server after end of data: 550 permanent failure for one or more recipients (user@.com:blocked) 2016-03-23 22:09:26 cwd=/var/spool/exim 7 args: /usr/sbin/exim -t -oem -oi -f <> -E1aiuiA-0007x0-Kz 2016-03-23 22:09:27 1aiuiE-0007xZ-SC <= <> R=1aiuiA-0007x0-Kz U=mailnull P=local S=2405 T="Mail delivery failed: returning message to sender" for user@.com 2016-03-23 22:09:27 1aiuiA-0007x0-Kz Completed
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  • cPanelMichael
    Could you verify the version of cPanel installed on this server? We've had a few cases that address the /etc/mailhelo and /etc/mailips files published in the past few weeks. Thank you.
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  • dreohio99
    We are on 54.0 (build 21)
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  • cPanelMichael
    Could you open a support ticket using the link in my signature so we can take a closer look? You can post the ticket number here so we can update this thread with the outcome. Thank you.
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  • alphawolf50
    Sorry about the delay. Ticket #7512403
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