On Sun, 16 Nov 2025, at 20:23, Riccardo Mottola via macports-users wrote: > I noticed in the past months/years that apple made several of my macs > stop connection. At first I ignored it, since I used those computers > less, but then when it tropped 10.9 first and 10.11 later it got me, > especially since the MacBook Pro 15" with 10.11 is one of my favourite > Macs and in Daily use.
https://support.apple.com/en-au/118308 > Minimum system requirements by feature > Calendar, Contacts, Mail > macOS High Sierra 10.13 (I know you mentioned your address book and calendar still work. Sadly, those things might also be living on borrowed time.) > Could it be missing certificates? Expired certificates? > I wonder if apple added some kind of "version" check in the mail > protocol to refules Mail connections? It makes no technical sense, but > could be an imposed marketing limitation? Perhaps the old Mac cannot negotiate an agreeable ciphersuite with the TLS servers that Apple are operating in 2025. Or maybe there is some 'new' signature algo causing problems. You can run a packet capture and inspect the TLS handshake to see what is going on. If you are unable to intercept traffic on a modern machine, you can try an old release of Wireshark; something in here should probably work on OS X 10.11. https://www.wireshark.org/download/osx/all-versions/ I like protocol analysers because they provide a mass of information in a way that is easy to navigate and read. Alternatively, if a packet capture is too finicky, you can check to see what openssl-s_client(1) says. Maybe it will give you a better error message than Apple Mail. Be sure to execute the OpenSSL release that came bundled with your Mac (and not a release from, say, MacPorts). /usr/bin/openssl s_client -host smtp.mail.me.com -port 587 -starttls smtp (There are like a bazillion flags in the manual; some expose more information.) Anyway, if you would like to continue using an old release of Apple Mail, it might be possible to install a modern TLS implementation and something like stunnel from MacPorts, then proxy all your IMAP and SMTP traffic through stunnel. Good luck!
