Javamail and TLS? (not STARTTLS)
jakarta-mail, java, ssl
Solution
The official examples for JavaMail with Gmail use SMTPS (i.e. SMTP over SSL/TLS on a dedicated port) and not STARTTLS. Essentially, the properties using JavaMail should be `mail.smtps.*` instead of `mail.smtp.*`.
If you want to force a specific version of SSL/TLS, for example TLSv1.0, you'll need to create your own `SSLSocketFactory`, possibly wrapping the default `SSLSocketFactory` (or anything else you would have customised), but you need to call `sslSocket.setEnabledProtocols(new String[] { "TLSv1" })` before returning the socket.
You'll need to pass that `SSLSocketFactory` either as an instance via the `mail.smtps.ssl.socketFactory` configuration property, or as a fully qualified class name via `mail.smtps.ssl.socketFactory.class` (in this case, you class must implement a static method called `getDefault`).
To prevent MITM attacks, you also need to make the client verify the server host name: you need to set `mail.smtps.ssl.checkserveridentity` to `true`, since it seems to be `false` by default.
Problem
I need to send an email using Javamail and TLS (not STARTTLS, but a dedicated smtp port just for SSL/TLS!). I only managed to find examples for gmail, that however use STARTTLS. Can somebody please post an example for normal SSL/TLS? Thank you very much!