Problems with Sendmail and Dovecot

I am using Fedora 17 running Sendmail with Dovecot. My problem is I can’t get Outlook or Thunderbird to connect to the server. Sendmail is accepting and sending mail by terminal command line with no problems. This is the error I get from Outlook when trying to test the connection:

“Log onto incoming mail server (POP3): Your mailbox is temporarily unavailable because another e-mail message is being delivered to it or another mail application is accessing it. The server responded: -ERR [IN-USE] Internal error occurred. Refer to server log for more information.”

Mail log displays this:
Jan 2 12:22:12 kipperdo dovecot: pop3-login: Login: user=<kip>, method=PLAIN, rip=68.14.209.149, lip=192.168.0.4, mpid=6475, TLS, session=<uBzRKVPSdgBEDtGV>
Jan 2 12:22:12 kipperdo dovecot: pop3(kip): Error: user kip: Initialization failed: Namespace '': Mail storage autodetection failed with home=/home/kip
Jan 2 12:22:12 kipperdo dovecot: pop3(kip): Error: Invalid user settings. Refer to server log for more information.
Jan 2 12:22:13 kipperdo sendmail[6476]: r02JMCsx006476: from=<kip@kipperdo.com>, size=0, class=0, nrcpts=1, proto=ESMTP, daemon=MTA, relay=wsip-68-14-209-149.ph.ph.cox.net [68.14.209.149]
Jan 2 12:22:13 kipperdo sendmail[6476]: r02JMCt1006476: from=<kip@kipperdo.com>, size=354, class=0, nrcpts=1, msgid=<201301021922.r02JMCt1006476@kipperdo.com>, proto=ESMTP, daemon=MTA, relay=wsip-68-14-209-149.ph.ph.cox.net [68.14.209.149]
Jan 2 12:22:13 kipperdo sendmail[6477]: r02JMCt1006476: to=<kip@kipperdo.com>, ctladdr=<kip@kipperdo.com> (1000/1000), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=30674, dsn=2.0.0, stat=Sent

Any help would be appreciated. Thanks,