Q:

Rails. Mass mail delivering

I have got about 1500 email addresses to send diplomas.
What should I use for bunch delivering nowadays? Ar_mailer looks out-of-date.

A:

I use delayed_job gem to send mail asynchronously.
https://github.com/collectiveidea/delayed_job

A:

This is a job for Madmimi: http://madmimi.com/
And a gem for easy interface: https://github.com/madmimi/madmimi-gem

