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Cpanel and exchange online protection mail loop

Discussion in 'E-mail Discussion' started by gym22, Sep 26, 2016.

  1. gym22

    gym22 Registered

    Mar 17, 2014
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    I need your help with a mail loop issue.
    I'm trying to impement Exchange onlinea protection (EOP) as anti-spam server in front of the cpanel account. I already configured the outgoing email (from cpanel account to the world ) to pass through EOP using the smarthost configuration and is working. The problem is when I try to configure inbound email that should be received on EOP at first and then delivered to the cpanel mailboxes. As I understand the configuration should be on the DNS entries and Email Routing option on cpanel (both on MX entry configuration)
    I found a similar configuration on the following URL:

    I followed this link recommendations and when the only MX entry on DNS is the "" record and the Email Routing option is on local mail exchanger all inbound emails failed to deliver with the following message (this message is replied by EOP to the sender):

    Hop count exceeded - possible mail loop

    Tracking email on EOP shows that Email arrives to the EOP server, and then try to route this email to the cpanel server, but this is returned to the EOP again.

    I tried different combinations with email routing and MX records but the problem persists.

    Hope someone has solved something similar previously as I have been looking for a solution without success for a while.

    #1 gym22, Sep 26, 2016
    Last edited by a moderator: Sep 26, 2016
  2. cPanelMichael

    cPanelMichael Technical Support Community Manager
    Staff Member

    Apr 11, 2011
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    There's discussion of this error message on the following third-party URL:

    Hop Count Exceeded – Possible Mail Loop

    Could you let us know if this helps to troubleshoot the problem?

    Thank you.
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