2.2.1-beta, Redhat 8; lmtpd continuously stuck on select( 0, ...)

[Joe Rhett]

Okay, I've had no drama at all getting recent versions of 2.2 to work like
a champ on Solaris, but Redhat appears to be a beast of a different color.

So the imap server is up and running and seems to be working.  Squirrelmail
is happy anyway ;-) But delivering mail to the system is hanging.  Running
deliver by hand hangs, and stracing deliver shows that it opens the LMTP
socket and then waits for a response.

strace of the running lmtpd process shows only:

select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)
select(0, NULL, NULL, NULL, {1, 0})     = 0 (Timeout)

$ lsof /var/imap/socket/lmtp
COMMAND   PID  USER   FD   TYPE     DEVICE SIZE    NODE NAME
master  24362 cyrus   19u  unix 0xc3c0a580      3308812 /var/imap/socket/lmtp
lmtpd   24376 cyrus    4u  unix 0xc3c0a580      3308812 /var/imap/socket/lmtp

The only thing related to this I can find -- and I'm not sure it's related
at all, is:
	http://www.irbs.net/internet/info-cyrus/0209/0163.html

I'm happy to debug this, but I need to know what to look for.  Tell me what
you need to know.

1. Is there anything about linux iptables that might intercept sockets?

2. What syntax can I put in cyrus.conf run lmtp in debug mode?  Or strace?
It does not appear to enjoy "strace lmtpd 2>&1 /tmp/lmtpd.debug" as the 
daemon to invoke.  Should I make this a script and redirect, or ..?
Also, Ken! I could have swore you put a "-v" in deliver a while back so that we could watch the LMTP conversation .. or am I misremembering?

-- 
Joe Rhett                                                      Chief Geek
JRhett at Isite.Net                                      Isite Services, Inc.