I found that all my messages are in /var/spool/clientmqueue.
I am also getting these messages on my /var/adm/messages log every time I try to send a messages:
Jul 1 09:25:24 hostname sendmail[25274]: [ID 801593 mail.info] k61EPO76025274: from=root, size=98, class=0, nrcpts=1, msgid=<200607011425.k61EPO76025274@hostname.testdomain.com>, relay=root@localhost
Jul 1 09:25:24 hostname sendmail[25274]: [ID 801593 mail.info] k61EPO76025274: to=name@testdomain.com, delay=00:00:00, mailer=relay, pri=30098, dsn=4.4.3, stat=queued
Please advise.