submit.cf (Sendmail 8.14.1 on Solaris 10)

Problem: you can send and receive email from outside of your localhost, but sending email to yourself or to local aliases fails. Syslog show errors similar to:

Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNJ016799: SYSERR(root): null destination for [IPC] mailer
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNJ016799: SYSERR(root): null destination for [IPC] mailer
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNK016799: SYSERR(root): null destination for [IPC] mailer
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNK016799: SYSERR(root): null destination for [IPC] mailer
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: [ID 801593 mail.info] l7AEPNNK016799: to=<root@concept.temple.edu
>, delay=00:00:00, xdelay=00:00:00, mailer=local, pri=31533, dsn=5.3.5, stat=Local configuration error
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: [ID 801593 mail.info] l7AEPNNK016799: to=MAILER-DAEMON, delay=00:00:00, mailer=local, pri=31533, dsn=5.1.1, stat=User unknown
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: [ID 801593 mail.info] l7AEPNNK016799: to=postmaster, delay=00:00:00, mailer=local, pri=31533, dsn=5.1.1, stat=User unknown
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: [ID 801593 mail.info] l7AEPNNK016799: l7AEPNNK016799: return to sender: User unknown
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNK016799: Losing ./qfl7AEPNNK016799: savemail panic
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNK016799: Losing ./qfl7AEPNNK016799: savemail panic
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNK016799: SYSERR(root): savemail: cannot save rejected email anywhere
Aug 10 10:25:23 concept.temple.edu sendmail[16799]: l7AEPNNK016799: SYSERR(root): savemail: cannot save rejected email anywhere

Run

/usr/bin/mailq -v -Ac

to see if sendmail complains about the submit.cf file

Warning: .cf file is out of date: sendmail 8.14.1 supports version 10, .cf file is version 0

Then double-check your /etc/mail/submit.cf file. I found that sendmail does not like

V10/Sun

in the submit.cf file. If you change it to just

V10

you will have better results.