The first line is sufficient
Please be aware that enabling port 587 only means that you can send a email with a smtp client fom a external source to your server now and not that your server is able to send emails outside, as port 587 is only used for incoming messages. So please see also what eko_taas mentioned.
If your provider offers a mail relay server, then you should use that mail relay server to send emails from your server. The details for the mail relay can be set under system > server config > email
Last edited by till; 1st November 2011 at 08:50.