Mail is not being delivered locally

Issue

• When mail is sent out, external addresses receive normally, but local addresses and root Logwatch emails are not delivered with the following error:

Oct  1 14:23:06 mysystem sendmail[27183]: q91IMxC8027183: to=testuser, ctladdr=root (0/0), delay=00:00:07, xdelay=00:00:00, mailer=relay, pri=30006, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]