Results from:
nano /var/log/mail.log
Mar 26 15:02:24 mail amavis[8553]: (08553-08) (!!)TROUBLE in process_request: Read from client socket FAILED: Connection reset by peer at (eval 96) line 173.
Mar 26 15:02:24 mail amavis[8685]: (08685-09) (!!)TROUBLE in process_request: Error writing a SMTP response to the socket: Connection reset by peer at (eval 97) line 987.
Mar 26 15:02:24 mail amavis[8553]: (08553-08) (!)Requesting process rundown after fatal error
Mar 26 15:02:24 mail amavis[8685]: (08685-09) (!)Requesting process rundown after fatal error
Mar 26 15:02:24 mail postfix/smtpd[10522]: connect from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10522]: NOQUEUE: reject: CONNECT from unknown[unknown]: 554 5.7.1 <unknown[unknown]>: Client host rejected: Access denied; proto=SMTP
Mar 26 15:02:24 mail postfix/smtpd[10522]: lost connection after CONNECT from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10522]: disconnect from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10519]: connect from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10517]: connect from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10517]: lost connection after CONNECT from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10517]: disconnect from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10519]: lost connection after CONNECT from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10519]: disconnect from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10519]: lost connection after CONNECT from unknown[unknown]
Mar 26 15:02:24 mail postfix/smtpd[10519]: disconnect from unknown[unknown]
Mar 26 15:05:44 mail postfix/anvil[10527]: statistics: max connection rate 1/60s for (submission:unknown) at Mar 26 15:02:24
Mar 26 15:05:44 mail postfix/anvil[10527]: statistics: max connection count 1 for (submission:unknown) at Mar 26 15:02:24
Mar 26 15:05:44 mail postfix/anvil[10527]: statistics: max cache size 2 at Mar 26 15:02:24
Mar 26 15:11:05 mail postfix/smtpd[10575]: connect from server.unet.com[83.170.92.95]
Mar 26 15:11:06 mail postfix/smtpd[10575]: 12A302467C: client=server.unet.com[83.170.92.95]
Mar 26 15:11:06 mail postfix/cleanup[10586]: 12A302467C: message-id=<22926885.42432.1395846653942.JavaMail.SYSTEM@server51348>
Mar 26 15:11:07 mail postfix/qmgr[1494]: 12A302467C: from=<b2bmail@b2bmailer.uk>, size=7505, nrcpt=1 (queue active)
Mar 26 15:11:07 mail postfix/smtpd[10575]: disconnect from server.unet.com[83.170.92.95]
Mar 26 15:11:07 mail postfix/smtp[10591]: 12A302467C: to=<myemail@otherdomain.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=1.7, delays=1.5/0.09/0.13/0, dsn=4.7.4, status=deferred (TLS is requ$