5 ms·

Thanks!

• justsomehnguy 4y ago
  Minor nitpicks: a) you need a plain-text aka telnet client for this b) if you receive a valid, human-readable text then it means what you are not on TLS for sure c) if B succeeds that doesn't means what that SMTP server support STARTTLS, you should check options and try to initite it , eg: 220 smtp.fastmail.com ESMTP ready -> EHLO just.testing.things 250-smtp.fastmail.com 250-PIPELINING 250-SIZE 71000000 250-ENHANCEDSTATUSCODES 250-8BITMIME !! 250 STARTTLS -> STARTTLS 220 2.0.0 Start TLS
  • imp0cat 4y ago
    Right, I guess you could also use openssl's s_client like this: openssl s_client -starttls smtp -connect smtp.gmail.com:587 openssl s_client -connect smtp.gmail.com:465