Does not support secure transport

[kfatehi]

Conventionally, mail sent on port 465 uses TLS, however strider-mailer does not have a way to enable secure transport.

In index.js there are two objects, smtpTransport and smtpConfig which together orchestrate nodemailer. The smtpTransport option could be modified per https://github.com/andris9/nodemailer-smtp-transport#usage to have {secure: true} if the port is 465.

Either that or we expose more configuration to the user through ENV

ref Strider-CD/strider#570

[knownasilya]

Is that the expected behavior? For it to be secure when on port 465?

[kfatehi]

That seems to be the convention as far as I've seen it in configs, etc, but I'd like a 2nd opinion