So I just migrated a bunch of accounts to the CentOS Deep Castle VM image. (Previously running on Windows)
If anyone attempts to send on port 25 they get a 501 permission denied after the MAIL FROM command.
501 5.7.1 <firstname.lastname@example.org>... Permission denied
The submission port 587 works, but there are still plenty of devices out there configured for port 25. For the moment I worked around this with a NAT rule. I can't figure out what settings are causing this. Any insights?
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