type session
upgrade_to_tls
is called when initiating an upgrade to TLS.
Session.greeting
will be called to send a suitable greeting after the upgrade.
val upgrade_to_tls : log:Async_smtp__.Mail_log.t ‑> session ‑> session Async_smtp.Smtp_monad.t
upgrade_to_tls
is called when initiating an upgrade to TLS.
Session.greeting
will be called to send a suitable greeting after the upgrade.