notify-*-mail: Enable SSL

[Kaliumiodid]

Describe the solution you'd like

Currently, the notify mail plugins only support unencrypted connections. My mail server only allows encrypted connections. It would be helpful, if the plugins notify-host-mail and notify-service-mail would support it, too. A solution might be another argument --ssl. If set, the connection would be made like this: s = smtplib.SMTP_SSL. If not set, it would stay like it is now s = smtplib.SMTP.

Additional context

No response