Check your server error logs first. You should also enable SMTP debugging to help debug mail issues if using SMTP. To enable, open the 'control/options.php' and set the following value to 1.
define('MAIL_DEBUG', 0);
The log should be written to the "logs" folder.
If you are having issues sending email over SSL, this is nothing to do with this software or the mail system used by this software. Most likely
your server's SSL is installed incorrectly. If you have issues, you can disable SSL checking in your mail settings (in favour of always allowing insecure connections). Whilst this is a workaround, it is NOT recommended.