FYI: A new (Jan 2018) RFC is now re-adopting port 465 for mail submission:
https://tools.ietf.org/html/rfc8314 It discusses the rationale, and it is the first RFC that I've found to be an interesting read. It advocates "Implicit TLS" on port 465 over either cleartext OR STARTTLS. On 4/10/2018 1:43 AM, Craig Skinner wrote: > Hi Nick, > > Port 587 is the proper MUA submission port, not 465. > > https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol > > https://tools.ietf.org/html/rfc6409 > > http://blog.mailgun.com/25-465-587-what-port-should-i-use/ > > > Port 465 is not RFC compliant. > > Perhaps Apple Mail expects the RFC port 587 to be operative? > > > Cheers, >
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