[AdamN]

I used to love Sendgrid but they seem to be slowing down development these days. Their interface hasn't changed much in the past few years and their Python libs/docs are ok but not great.

If I were sending lots of email like I used to I would consider SES but for the small volumes I'm doing now it seems like Sendgrid and Mailgun are good enough. Postmark.app gets some positive reviews in the comments so maybe people should give them a shot.