Fun with new mailservers


I’m building a new set of mailservers for – our existing mailserver was “I’ll repurpose this test box for a week” about four years ago, so it’s long past time.
I tested our new smarthost by sending a test mail to gmail. This is the very first email this IP address has sent in at least three or four years, possibly forever:

host[] said:
421-4.7.0 [      15] Our system has detected an unusual rate of
421-4.7.0 unsolicited mail originating from your IP address. To protect our
421-4.7.0 users from spam, mail sent from your IP address has been temporarily
421-4.7.0 rate limited. Please visit
421-4.7.0 to review our Bulk
421 4.7.0 Email Senders Guidelines. u2si19966404pbz.202 – gsmtp (in reply to end of DATA command)

Sigh. IP warmup is hard.
I spun up our new MX and within three minutes, before I’d sent any test mail myself, I was seeing relay tests from the therichsheick spammer. Still scanning for open relays, still using the same Yahoo addresses. Followed immediately by someone else doing the same thing using gmail addresses.

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  • Isn’t that interesting? At AOL, we had a special error just for new IPs. I wonder if Gmail gives this “Our system has detected an unusual rate of unsolicited mail originating from your IP ” error to new IPs. That would sort of make sense, at least the “unusual rate” part. The error message is kind of odd in general. It seems to say “you always send unsolicited mail, but now we’re seeing more of it, so we’re blocking you.”

  • The error message is a little odd. And eight hours later they’re still deferring delivery attempts for that message.

By steve

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