Gonna need more than just 25/tcp (SMTP). Will also need 465/tcp (SMTPS) and 587/tcp (SUBMISSION)... and you'll need to tie it to the user's IP/block obviously.... otherwise you'll have a LOT of unhappy users.
Further commentary can be found here: https://www.mailgun.com/blog/which-smtp-port-understanding-ports-25-465-587/ On Sat, Feb 5, 2022 at 10:10 PM Steve Jones <[email protected]> wrote: > Ive been intending to block it inbound/outbound for some time. in 2022, > other than mail server theres no legitimate reason to use that port. > > > On Sat, Feb 5, 2022 at 9:22 PM TJ Trout <[email protected]> wrote: > >> Yes, or on the customer's router, either way. We block 25 but I'm not >> sure that is customary nowadays? >> >> On Sat, Feb 5, 2022 at 5:45 PM Chuck McCown via AF <[email protected]> >> wrote: >> >>> Would that be something you would configure in the border/edge router? >>> >>> *From:* TJ Trout >>> *Sent:* Saturday, February 5, 2022 6:32 PM >>> *To:* AnimalFarm Microwave Users Group >>> *Subject:* Re: [AFMUG] Blocking email servers >>> >>> block port 25 outgoing >>> >>> On Sat, Feb 5, 2022 at 5:23 PM Chuck McCown via AF <[email protected]> >>> wrote: >>> >>>> What is the best way to prevent customers from running their own email >>>> server? >>>> >>>> -- >>>> AF mailing list >>>> [email protected] >>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>> >>> ------------------------------ >>> -- >>> AF mailing list >>> [email protected] >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> -- >>> AF mailing list >>> [email protected] >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >> -- >> AF mailing list >> [email protected] >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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