The client has their email hosted by Intermedia. Intermedia stopped accepting unauthenticated email on port 25. They had a fax server running HylaFax running on Gentoo. At first they were getting an error about not being able to connect. I checked with Intermedia and they changed servers, so I changed the target host from to point to east.EXCH083.serverdata.net instead of smtp15.msoutlookonline.net.
The new host requires authenication, so I followed this guide:
https://ubuntu-tutorials.com/2008/11/11/relaying-postfix-smtp-via-smtpgmailcom/
now in the maillog, I'm getting:
Dec 6 19:37:36 fax postfix/qmgr[5395]: A2CF5434A38: from=<fax@<domain>.com>, size=4466, nrcpt=1 (queue active)
Dec 6 19:37:37 fax postfix/smtp[8215]: A2CF5434A38: to=<user@<domain>.com>, orig_to=<FaxMaster>, relay=mail[xx.xx.52.35]:25,
delay=13170, delays=13169/0.01/0.25/0.1, dsn=4.7.1, status=deferred (host mail[xx.xx.52.35] said: 454 4.7.1 <user@<domain>.com>:
Relay access denied (in reply to RCPT TO command))
So that tells me that it's trying to connect on port 25, not 587 like I put in the file /etc/postfix/main.cf
Where do I go from here?