SUMMARY: Sendmail 8.6.9 Delays with POP2 Posts?

From: Lawrence Houston (
Date: Thu Nov 10 1994 - 04:02:41 CST

SUN Managers:

Original Posting:
Recently installed Sendmail 8.6.9 with BIND 4.8.3's Resolver Routines
added to LIBC (bindon41) on a SPARC 2 running SunOS 4.1.3 and am
experiencing long delays (up to 30 seconds) when E-mail is being posted by
a POP2 Client (POPmail 3.1)! Moving back to my LIBC with SMI's own
resolver routines added in (Greg Earle) does NOT relieve the problem, but
moving back to SMI's MX Sendmail DOES! Does anyone know where these
delays might be coming from? Whether they can be corrected with changes
in 8.6.9's, recompiling Sendmail or the BIND Resolver

Not sure if these delays are related Sendmail 8.6.9 being installed under
SunOS or if there are purely a Sendmail 8.6.9 problem. If it is the
later, I hope people can be forgiving and point me to a more propropriate

Thanks those who replied:

Casper Dik <>
Claus Assmann <>
Sean Steppie <>
Brad Knowles <>
"Saad M. Waraich" <waraich@Biostat.Wisc.Edu>

It turns out to be a strickly a Sendmail "feature", but I will post a
summary to the SUN Manager's List as 8.6.9 seems to be preferred
replacement for SMI's own offering.

Sendmail 8.6.9 compiles with "Identification Protocol" RFC1413 enabled by
default. With IDENTPROTO enabled the sending host's "identd(8)" daemon is
queried in an attempt to identify the UID of the sending MTA. With a POP
Client such as POPmail 3.1 running under DOS (which does NOT support the
IDENT Query), 8.6.9 will time-out after 30 seconds before accepting the
SMTP Post!

As Saad said:

You can:
        go back to using sun's sendmail (bad)
        disable rfc 1413 compliance in (bad)
        use a decent transport/network layer on your pc's, i.e. one
        which complies with the ident protocol.

The later would be the best solution as it maintains this added level of
security that IDENTPROTO is intended to add, as it attempts to identify
who if really sending the E-mail. Not sure of IDENTPROTO's true value, as
may sites will normally run their Sendmail SUID to Root anyway?

My solution was to recompile 8.6.9 with the IDENTPROTO disabled:

by adding the following line to conf.h:

# define IDENTPROTO 0 /* disable ident support for POPmail */

or as Sean suggests:

In the Makefile on the CFLAGS line add -DINDENTPROTO=0 so it looks
something like :


then do a make clean and make !

Both should have the same result? As it turns out this subject was
recently discussed on USENET "comp.mail.sendmail", but I was NOT
subscribed to that group until more recently!

Lawrence Houston - (

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