> > On a separate note, I'm far from a mail expert, and, am happy to > > be corrected, but, I was under impression that port 465 for smtp > > had been deprecated since...late 90ies?, and, submission port 587 > > is the preferred and appropriate port? > > > > Port 465 is what is used if you're using ssl/tls. If you're going > with starttls it's 587. There are those who prefer starttls/587 (and > yes, technically 465 is depreciated), but not all clients support > that. Google/gmail's submission settings are ssl/tls port 465 -- see: > > <https://support.google.com/mail/troubleshooter/1668960?hl=en> > > (you'll have to make selections, e.g., imap/android (with javascript > on) to see the final settings page.) > > The problem that I see with starttls is that if you don't set your > client to require it (and rather take an "if available" option) you > don't really know if your connection is encrypted (unless you're > running the server). K-9 dropped the "if available" option for > starttls with the recent update so anyone who was previously using > the K-9 "starttls - if available" setting and is now having problems > should probably select "none" as I suspect their server wasn't/isn't > really doing starttls. >
Richard, Thanks. Yes, I've seen different mail clients won't accept all 'valid' combinations, like, with Outlook, I don't think you can do pop/imap SSL/TLS except on 993/995, whereas with other clients you can do on 110/143, etc, etc Googling came up with Stackoverflow, it has this: --------------- These port assignments are specified by the *Internet Assigned Numbers Authority (IANA)*: Port 587: *[SMTP] Message submission* (SMTP-MSA), a service that accepts submission of email from email clients (MUAs). Described in RFC 6409. Port 465: *URL **Rendesvous** Directory for SSM* [sic] *(entirely unrelated to email)* Historically, port 465 was initially planned for the *SMTPS* encryption and authentication “wrapper” over SMTP, but it was quickly deprecated (within months, and over 15 years ago) in favor of *STARTTLS* over SMTP (RFC 3207). Despite that fact, there are probably many servers that support the deprecated protocol wrapper, primarily to support older clients that implemented SMTPS. Unless you need to support such older clients, SMTPS and its use on port 465 should remain nothing more than an historical footnote. The hopelessly confusing and imprecise term, *SSL*, has often been used to indicate the *SMTPS* wrapper and *TLS* to indicate the *STARTTLS* protocol extension. For completeness: Port 25: *Simple Mail Transfer* (SMTP-MTA), a service that accepts submission of email from other servers (MTAs or MSAs). Described in RFC 5321. --------------- -- -- You received this message because you are subscribed to the K-9 Mail Users List. To post to this group, send email to [email protected] To unsubscribe, email [email protected] To report an issue with K-9 Mail, visit http://code.google.com/p/k9mail/issues/list For more options, visit this group at http://groups.google.com/group/k-9-mail --- You received this message because you are subscribed to the Google Groups "K-9 Mail" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
