Sending requires quite a large volume for the big players to allow you to play. The only viable option for small servers is to use a SMTP relay service. Amazon'

Sending requires quite a large volume for the big players to allow you to play. The only viable option for small servers is to use a SMTP relay service. Amazon's was a pain to get out of the sandbox mode but has been reliable and most importantly free. As I care more about the recieving side than sending emails this works well enough for me.