iyzsong@outlook.com schreef op za 12-03-2022 om 10:22 [+0800]:
> +   "Specify the encryption to use, either @code{ssl} or @code{tls}.  Any other
> +value reverts to plain SMTP.")

This seems easy to go wrong, e.g. what if I accidentally pass a value
in uppercase, e.g. "SSL" or "TLS"?  I recommend validating this value
instead of silently not encrypting.

Also, does this need to be a symbol, or a string?  Looking at the
documentation, I would expect a symbol, but looking at the
implementation, it seems to have to be a string.

Greetings,
Maxime.