[Dovecot] Freebsd 4 error DSN stat=Service Unavailable after dovecot install

[Biffy Bob]

Hello everyone,
I am getting an error message on FreeBSD 4 after I install dovecot.  To 
start off, I create two regular users, testuser and testuser1.

I send each user emails then I install dovecot.  After installing 
dovecot I set up the users in Maildir format then proceed to send them 
emails and here is what shows up in the maillogs:
Email to testuser3 -
Mar 29 22:34:52 myserver sendmail[4379]: l2TMYqwj004379: from=root, 
size=54, class=0, nrcpts=1, 
msgid=<200703292234.l2TMYqwj004379 at myserver.vwh.net>, relay=r
oot at localhost
Mar 29 22:34:52 myserver sm-mta[4380]: l2TMYqMi004380: 
from=<root at myserver.vwh.net>, size=342, class=0, nrcpts=1, 
msgid=<200703292234.l2TMYqwj004379 at myserver
.vwh.net>, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]
Mar 29 22:34:52 myserver sendmail[4379]: l2TMYqwj004379: 
to=testuser3 at myserver.vwh.net, ctladdr=root (0/0), delay=00:00:00, 
xdelay=00:00:00, mailer=relay, pr
i=30054, relay=localhost.. [127.0.0.1], dsn=2.0.0, stat=Sent 
(l2TMYqMi004380 Message accepted for delivery)
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMi004380: 
to=<testuser3 at myserver.vwh.net>, ctladdr=<root at myserver.vwh.net> (0/0), 
delay=00:00:00, xdelay=00:00:0
0, mailer=local, pri=30560, relay=local, dsn=5.0.0, stat=Service 
unavailable (something didn't work)
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMi004380: l2TMYqMi004381: 
DSN: Service unavailable (something didn't work)
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMi004381: to=myserver, 
delay=00:00:00, xdelay=00:00:00, mailer=local, pri=31584, relay=local, 
dsn=5.0.0, stat=Se
rvice unavailable (something didn't work)
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMi004381: l2TMYqMj004381: 
return to sender: Service unavailable (something didn't work)
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMj004381: to=myserver, 
delay=00:00:00, xdelay=00:00:00, mailer=local, pri=32608, relay=local, 
dsn=5.0.0, stat=Se
rvice unavailable (something didn't work)
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMi004381: Losing 
./qfl2TMYqMi004381: savemail panic
Mar 29 22:34:52 myserver sm-mta[4381]: l2TMYqMi004381: SYSERR(root): 
savemail: cannot save rejected email anywhere

Here is what the user looks like in /etc/passwd:
testuser3:*:2400:2400:My very own test user:/home/testuser3:/sbin/nologin

For the other users that have shell access, they don't get this 
problem.  It seems to be only the users with no shell.
Does anybody know of a fix for this problem?