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Outgoing mail queues on yahoo mail

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  • Outgoing mail queues on yahoo mail

    We just wondering why we are experiencing huge out-going mail queues on yahoo mail. We can sent emails to other domains eg. gmail without any delays.
    I just thinking that yahoo is blocking/restricting our domain.
    Any thoughts?


  • #2
    Re: Outgoing mail queues on yahoo mail

    They're probably graylisting your email. If they were blocking it you wouldn't have emails in the queue to them as those emails would be refused and your server would generate an NDR to the sender. Check your SMTP logs on the Exchange server for any connections to Yahoo email servers. In my experience with Yahoo graylisting, their SMTP servers state the graylisting in the SMTP conversation along with the SMTP status code. You can then go to their postmaster web site and request that they stop graylisting you.


    • #3
      Re: Outgoing mail queues on yahoo mail

      I wasn't aware that Yahoo used greylisting.

      In fact Yahoo themselves deny it.

      It sounds like Yahoo are simply blocking traffic from your IP address - remember blacklisting is NOT done on domain level, otherwise everyone would be blackmailed by the spammers.

      The message on the queue in ESM may give you an idea as to what the issue is, you should also check whether you are blacklisted and that your DNS is setup correctly - SMTP banner, SPF record if used and reverse DNS.

      Simon Butler
      Exchange MVP

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      • #4
        Re: Outgoing mail queues on yahoo mail

        I could be mistaken but I could swear I had a couple of instances where Yahoo graylisted our emails. Anything in the SMTP logs going to Yahoo?


        • #5
          Re: Outgoing mail queues on yahoo mail


          Problem is now solved by changing DNS on Exchange Server.