Add more mail integration options, since mail services have increased their prices.

Since Mailchimp and AWeber have decided to increase their prices ridiculously, a lot of us are switching to other mail services. It would be great to have more integration options with Beatstars besides just AWeber and Mailchimp. I switched from Mailchimp to Mailer Lite right now (no is no promotion for them) which is $17 instead of $55 at Mailchimp for example. But at the moment, we are kind of "forced" to use AWeber and Mailchimp because those 2 are the only mail integration options.