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Email blocked by mystery

Discussion in 'E-mail Discussions' started by Lyttek, Apr 14, 2010.

  1. Lyttek

    Lyttek Well-Known Member

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    I have a client whose parent company is based in the Netherlands. Their corporate email servers are located at IP 195.193.60.11 and 195.193.60.244

    Email from my server at 66.39.200.26 gets to them just fine. They cannot send me email. I've had them try manual connections on ports 25 and 587... no dice.

    I've added their IP addresses to csf.allow, but can't see that it's blocking them anywhere anyway. Their IPs are not listed in any blacklist I can find.

    The attached shows what they're seeing from their end when they sniff the traffic.

    The IP 66.39.192.14 is the last hop before my server. They are able to do traceroutes just fine.

    Any thoughts on where to check? They're not in the csf.deny file...

    :confused:
     

    Attached Files:

  2. thobarn

    thobarn Well-Known Member

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    I was able to telnet to 66.39.200.26:25. Since they can traceroute but cannot email, and from the capture, looks like 66.39.192.14 is filtering email traffic from 195.193.60.11. Talk to 66.39.192.14 server admin
     
  3. Lyttek

    Lyttek Well-Known Member

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    I'd had a call in to my colocation provider but hadn't heard back when I first posted.

    You were correct in your assessment.

    Without so much as telling me, they'd blocked a whole range of IP addresses from smtp to stop a flood of spam from the Netherlands.

    I've asked them to report to me any other blocking they're doing... and asked why they hadn't notified me of this. :mad: :mad:

    So, my upstream provider was the problem.
     
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