spam or crazy mail server changes?

I'm still getting lots of SMTP hits from varying servers attempting to deliver
mail to my tagged email address, used only for subscribing to this list. The
delivery attempts are using the same envelope sender address style as is used
by the list itself. But is this real mailing list attempts from a messed up
server or network, or is it a slick spammer doing a smooth job of faking the
mailing list in every way but a validated reverse DNS?

I have "postgresql.org" whitelisted, so mail delivery from a mail server that
has a reverse DNS of a name that contains the peer address among its A records
will succeed. Any address with no reverse DNS, or has reverse DNS that does
not validate, and is from an IP address that is not whitelisted, will fail.
Other addresses may or may not fail, depending on other information.

If these attempts are really a spammer desperately trying to send me several
messages a day, I'll take it up with the hosting ISPs. But if it is another
mail server for this list that isn't set up right (as defined by what it takes
in a spam filled world to rise above the spam), I may just have to leave this
list and move on. It's just not practical to keep whitelisting new IP addresses
every week.

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| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
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