[Mailman-Users] phantom subscription requests

[David Newman]

Mailman 2.1.12 on OpenBSD 4.5

Don't know if this is a coincidence, but ever since rebuilding a Mailman
server that crashed last week and restoring the lists from archives, the
site admin address has received a few dozen bogus subscription requests
to lists on that server.

This is odd, in that I'm site admin and have not sent any such requests.
>From the little bit of spot checking I've done, the requests appear to
come mostly from machines in RIPE space in Europe.

Is anyone else seeing this? What measures, if any, can a site admin take
to block bogus subscription requests?

thanks

dn