ETRN help

[Kevin Spicer]

On Mon, 2003-11-10 at 15:53, Brandon Friedman wrote:

>We have sendmail setup for mailspooling i.e. some server connect and
>issue
>the etrn command. We have removed the noetrn option from the init file
>but
>still mail is not being allowed to etrn... any ideas?

Yes, there is a very good reason why the noetrn option is in the init
script, it should not be removed.  ETRM commands are received by the
_listening_ sendmail process and cause it to run its queue looking for
messages for the appropriate domain.  Because mailscanner splits the
sendmail process this means issuing a ETRN actually causes the listening
sendmail process to run the incoming queue (which is its queue) - this
means it will only deliver mail that has not yet been scanned, mail that
has been scanned sits happily in the outgoing queue.  Because the
outgoing queue belongs to a different sendmail process it is unaffected
by the ETRN commands issued to the incoming sendmail.
In actual fact allowing ETRN also causes additional serious problems, it
introduces a race condition that can lead to the receipt of partial
messages.