A considerable number of list subscribers' mail servers rejected today's two 
postings from "tao", complaining about the mail header not being RFC 2822 
compliant. Apparently the error was that the To: field 
contained "[EMAIL PROTECTED]" (note the explicit root domain final dot). 

Indeed this is a syntax error (despite the fact that including that dot is 
generally allowed), but I thought I'd make you aware that strict syntax 
checking might be too, well, strict, and cause false positives (and strong 
language such as "Header syntax of YOUR e-mail is invalid! Go home, read RFC 
2822 carefully and check YOUR mail!" might be a bit too abusive).

I haven't checked whether any or all of the MTAs in question run Exim, but 
another common false positive I've noticed when using verify = header_syntax 
is addresses of the form "[EMAIL PROTECTED] <[EMAIL PROTECTED]>", 
which some MUAs generate when no display name is entered.

Speaking of dubious anti-spam measures, it also seems that some servers return 
temporary status codes when they don't like the message content. It seems 
like that because they consistently returns 45x after end of DATA for some 
messages (or at connect, if they don't like the connecting host; Yahoo seems 
to do this, for example), while accepting all other messages right away. If 
it's not going to be accepted ever, a permanent status code should be 
returned. The error messages don't always provide a specific reason, so it 
might also be that some emails trigger some unexpected problem.

In any case, whitelisting 131.111.8.192 and other trustworthy mailing list 
servers, if you can, should be a good idea. 99.9-100% of all spam that makes 
it through to Mailman is held there, due to the sender being unknown, and 
subsequently discarded by the moderators. Rejecting list mail not only means 
that you miss it, but also that you risk being unsubscribed.

-- 
Magnus Holmgren        [EMAIL PROTECTED]
                       (No Cc of list mail needed, thanks)

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