[Mimedefang] Verizon and greylisting
mimedefang at nabs.net
Sun Dec 24 14:51:36 EST 2006
On 24 Dec 2006 at 12:54, Joseph Brennan wrote:
> The message comes into the list host with the writer of the message
> as MAIL FROM. The bounce goes out of the list host as MAIL FROM:<> and
> RCPT TO the several list owners.
Correct, but for most list owners, the list host is generally going to
be "internal" with respect to the gateway running MIMEDefang, it's not
much of an issue.
> David makes a good point though about smaller systems. You might
> happen to know that no two people on your system are co-list-owners.
In the rare cases where there are multiple list owners who aren't
forwards from "internal" users (for example, the owners of
"biglist at somewhere.tld" would likely all have "@somewhere.tld" accounts
that actually get the mail to start with, and this might then be
forwarded to other domains throughout the world), there might be a time
when you get two recipients for a DSN, but some mailing list software
now uses some other "special" sender for list bounces to owners.
It really doesn't matter, though, since the second owner would just be
tempfailed, so it would eventually get through. Only a non-conforming
sending implementation would be a problem, so any real mailing list
would work fine.
My method makes disabling "VRFY" be more useful than if you still allow
multiple recipients for mail from "<>".
Sure, you get more chances to filter because of the lack of milter
callbacks with "VRFY" and the ability to greylist From/To/IP, but it's
still less effective.
Jeff Rife |
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