Mandrill
PostMark
Sparkpost
Mailgun
Sendgrid
Amazon SES
PepiPost
And we have chosen Mailgun and Sendgrid as alternative to mandrill. With AMazon SES also for high volumes.
Sparkpost has some problems for transactional emails but you can read all the info on the post.
https://sendyhost.com/mandrill-alternatives-245/
We have compared:
Mandrill PostMark Sparkpost Mailgun Sendgrid Amazon SES PepiPost
And we have chosen Mailgun and Sendgrid as alternative to mandrill. With AMazon SES also for high volumes. Sparkpost has some problems for transactional emails but you can read all the info on the post.
Maybe it can help others. Cheers!