Actually, screw my previous comment. I take it back. They require business verification, and you have to jump through all these hoops for them to allow you to use their service, then beg them "oh pretty please" let me use your service oh wise Rackspace gods. Sod that, no time for that.
SendinBlue is cost effective and easy to use for email marketing
Sendinblue made email marketing easier with a lot of features and functions.
I tried to add a second email to my account and it went straight into spam. Then the confirmation link inside didn't work (404). Then whitelisting my local domain didn't work, so now I'm stuck. Therefore, I have no interest in going any further as I can't be bothered waiting around for them to fix things.
I bought sparkpost and they have some problem working with interspire which i got to know later. I asked them to give me time to fix things as i use interspire and you are the only one who need a patch to be added. Neither they refunded and keep billing me for no use. and nor they replied to my request. Handle with care.
voted for @Sendgrid !