[ietf-dkim] MLMs and signatures again
hsantos at isdg.net
Thu May 26 15:45:55 PDT 2011
Murray S. Kucherawy wrote:
>> Franck Martin
>> side note: do
>> mail receivers treat mailing list differently than any other emails?
> That's a local policy question. Personally, I don't know of any
> that do.
Almost all SMTP receivers that have an acceptable table and if the
operator has a separate list server running on the system, the list
server can use this acceptance table to update it for the MTA server
to use. Since RCPT TO checking is increasingly done, this is necessary
otherwise the list address is unknown to the receiver. If the mail is
accepted unchecked, then a post smtp processor also checks the table.
It could also queue the mail for a list which the list server is
eyeballing and it does the checking.
>> 2) do we need a mechanism to alert the receiving MTA that you have
>> subscribed to a mailing list, and all messages should pass through?
> Certainly a possible feature, but it seems like it won't scale
> very well.
That is what was said in the past to not do RCPT TO checking. That
changed with the advancements in hardware and Multi-threaded OSes. As
you know, database lookups are darn fast and scale.
The only reason we don't do it with our wcSMTP server and wcListServer
is because the list server is sold separately and doesn't need our
wcSMTP server. But an integrated database hook can be added.
Probably the other reason is that we don't want to have an official
SMTP reject, and want the list server to create a non-bounce
notification. But I can see where this be a good idea to do now -
SMTP level rejects with response text "User not member of so and so list."
Hector Santos, CTO
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