Good day. I have a client whose solution sends a pretty good volume of transactional emails (mostly notifications of system events or reminders to specific users or customers). We're looking at moving away from plugins to web services to solve a number of annoying problems.
I've seen at least a few different services, including Mailgun, Sendgrid, and Postmark. Does anyone have experiences with these they care to relate? We do need to send HTML mail with attachments, so that factors in. Also, ease of integration is a concern. I don't have a lot of experience with web services, so a dummy-friendly one would be helpful.