I see that that ISPs are starting to push users to use SMTP port 587 instead of old port 25. Spam usually appears in the ISP’s reason for this need. My question is “how is this going to stem the spam tide?”
- Is this because 587 typically employs authentication? But some ISPs
don’t require authentication on that port. Also, can’t 25 be configured to require user authentication as well? - Is this because 587 can use certificates? Aren’t the certificates server-side rather than client-side?
- Is this to stop ‘legacy’ spam-bots? Won’t the spammers just adapt?
What am I missing here? My Google searches return a lot of ‘how to fix your port 25 issues’, but very little ‘why’.
