SMTP Email

Hmmm... after testing with with my two providers authsmtp.com and Amazon Web Services SES I can see a can of worms opening.

I see you are using port 465. With Amazon SES I can use port 465 with SMTPCrypto set to 'ssl', but not with 'tls'.
Using port 587 I can connect using SMTPCrypto = 'tls'.

Complicating things further, I see that RFC8314 (section 3.3) specifies that the TLS handshake should start immediately and not wait for STARTTLS. So, as I understand it - if port 465 is used, 'ssl' should be specified to connect securely from the start and thus SMTPCrypto='ssl' is required. If using port 587, connection is initially made in cleartext and then STARTTLS is used to switch to securecd connect.

If you change SMTPCrypto to 'ssl' and keep port 465 does it work for you?
Alternatively: if you switch to port 587 (provided you ISP supports it) and keep 'tls' does it work for you?

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Also, I see that Amazon SES doesn't allow using STARTTLS when connected to port 465. It replies with "454 TLS not supported". AuthSMTP accepts STARTTLS even on port 465 (suggested in the RFC for backward compatibility). Changing cipher mid-connection has proven to be a bad idea so I guess Amazon is extra cautious.