[ic] Inconsistently unable to send with sendmail

[Aaron Berg]

I have a catalog with occasionally is unable to send with sendmail.  I
don't know why this is.

The system is a P4 3GHz (hyperthreading enabled) with 1GB RAM, 60GB+
free disc space. There is only one catalog running on the server.
TRAFFIC is set to high.  The site does about 16GB of traffic per
month.

MTA is sendmail 8.12.1
Distro is Redhat Enterprise.
Kernel is 2.4.21
IC is 5.4
Perl is 5.8.8 non threaded

Some mails are logged in error.log like:
....catalog /cgi-bin/catalog/ord/finalize.html Unable to send mail
using /usr/sbin/sendmail

Some order confirmations that are logged like this did acctually get
sent, but most do not.  Does IC try to send more than once if there is
a failure?

The mails that fail to send don't generate anything in either messages
or maillog, just the 'unable to send' in error.log.

Anyone have any ideas or can point me in the right direction?  There
are postings in the archive about this, but I couldn't find any with a
resolution.


Thanks.