I hang out on the SourceForge-hosted
inkscape-user mailing list,
where I pick up useful tips for the Inkscape
SVG editor (vector drawing program).
For months, the list has been plagued with spam; largely because anyone can
send to the list. The policy has been not to require new users to sign up
for the list before being able to send questions. This is commendably
friendly and user-centric, but the spam has become a real annoyance.
One of the Inkscape developers finally said that, if a dozen or more people
said "yes, restrict posting to list members only" and no-one opposed it, he
would lock the list down. I attempted to vote yes and got the following
rejection letter from SourceForge:
<inkscape-user@lists.sourceforge.net>:
66.35.250.206 does not like recipient.
Remote host said: 550-Postmaster verification failed while checking <george@reilly.org>
550-Called: 205.158.62.206
550-Sent: RCPT TO:<postmaster@reilly.org>
550-Response: 550 <postmaster@reilly.org>: User unknown
550-Several RFCs state that you are required to have a postmaster
550-mailbox for each mail domain. This host does not accept mail
550-from domains whose servers reject the postmaster address.
550 Sender verify failed
Giving up on 66.35.250.206.
Such irony! I had received a similar bounce a few days before from the
FlexWiki-Users
mailing list, which is also hosted by SourceForge, when I announced
Vim Syntax Highlighting for FlexWiki.
I don't own the reilly.org domain. It (and thousands of others) are
owned by NetIdentity. I had an exchange
with their postmaster, who said in part:
I did talk to sourceforge. They claimed it is an essential part of their spam
filtering process to reject domains that dont have a postmaster mailbox.
I've tried that (at least on a test basis) myself and with all due respect to
them, it is passe' ... doesnt work too well. And it has the added "advantage"
of having to connect back to the sending mail domain every time to see if a
postmaster for that domain exists. This holds up email and creates additional
smtp connections - and hence even more load on mailservers, in the case of
domains - with postmaster up and running - that are forged into spam.
I did suggest a few more rather efficient (and practical) filters they could
use, but well, they didnt respond to those
He has since added a postmaster mailbox for reilly.org, so I can post to
SourceForge lists again.
The Inkscape vote passed, of course. Only subscribers can post now.
Non-subscribers can also use a webform to send questions, so it's not a big
impairment.