[mtlynch]

Postmark is owned by Active Campaign, which was included in OPs list, though I'm not sure how the Postmark product differs from the original Active Campaign product.

I've been using Postmark for hobby projects for the past three years, and I've been happy with them, but my needs are super minimal - just sending out <100 emails per month programmatically where latency doesn't matter.

[cess11]

A previous employer used Postmark around the time they got acquired, I recommended they find another supplier but left sometime after.

Back then they were rather convenient and we didn't have any problems with tainted IP addresses, not sure if their new rather villainous owner has changed the Postmark business. I kind of expect them to pull IP addresses in through the email sending business to build reputation and then promote them to the ad delivery business.