John R Levine <johnl@iecc.com> writes:
>
>This is two separate deliveries which may or may not be the same message,
>but instead of tearing down a virtual circuit and immediately setting up a
>new one to the same place, it reuses the one that's already open. It
>looks to me like this is clearly a win, since you avoid the teardown and
>setup packets, and RSET/250 is one round trip, whereas QUIT/221 and then
>220/EHLO/250 is two and half.
>
>Is there any structural reason why qmail couldn't do this? Exim looks at
>the outgoing queue and if it sees a suitable message, re-execs itself
>with a flag so it knows its connection is already open.
>
Isn't this already done via maildir2smtp in the serialmail package?
Admittedly, it's not automatically there when you install qmail.
It's necessary to configure delivery to a maildir and relaying
via maildir2smtp, but it appears to meet the network behavior
criteria you (and others) gave.
The example someone gave for their 17K mailing list showed only
7 or 8 sites that would need such treatment, which is not an
undue configuration load for the admin.
The main refinement I can think of for this method would be to
give maildir2smtp the ability to lookup and follow (at startup
time only) any MX records for the target domain. That way, when
the target site has multiple MX hosts, the currently available
one can be found and used. As an alternative, perhaps a wrapper
that performs the lookup and invokes maildir2smtp on the series
of target IP addresses until a successful connection is made or
the list runs out.
(I'll probably find myself trying to write a wrapper like that
fairly soon)
-Greg
--
Greg Andrews West Coast Online
Unix System Administrator 5800 Redwood Drive
gerg@wco.com Rohnert Park CA 94928
(yes, 'greg' backwards) 1-800-WCO-INTERNET
>
>This is two separate deliveries which may or may not be the same message,
>but instead of tearing down a virtual circuit and immediately setting up a
>new one to the same place, it reuses the one that's already open. It
>looks to me like this is clearly a win, since you avoid the teardown and
>setup packets, and RSET/250 is one round trip, whereas QUIT/221 and then
>220/EHLO/250 is two and half.
>
>Is there any structural reason why qmail couldn't do this? Exim looks at
>the outgoing queue and if it sees a suitable message, re-execs itself
>with a flag so it knows its connection is already open.
>
Isn't this already done via maildir2smtp in the serialmail package?
Admittedly, it's not automatically there when you install qmail.
It's necessary to configure delivery to a maildir and relaying
via maildir2smtp, but it appears to meet the network behavior
criteria you (and others) gave.
The example someone gave for their 17K mailing list showed only
7 or 8 sites that would need such treatment, which is not an
undue configuration load for the admin.
The main refinement I can think of for this method would be to
give maildir2smtp the ability to lookup and follow (at startup
time only) any MX records for the target domain. That way, when
the target site has multiple MX hosts, the currently available
one can be found and used. As an alternative, perhaps a wrapper
that performs the lookup and invokes maildir2smtp on the series
of target IP addresses until a successful connection is made or
the list runs out.
(I'll probably find myself trying to write a wrapper like that
fairly soon)
-Greg
--
Greg Andrews West Coast Online
Unix System Administrator 5800 Redwood Drive
gerg@wco.com Rohnert Park CA 94928
(yes, 'greg' backwards) 1-800-WCO-INTERNET