A bit of a backstory. Postmark was a delivery first company. Initially they were actually transaction email ONLY (not even product updates, release notes). They broadened eventually, but manually reviewed each new customer AND if you were doing marketing often pointed you elsewhere
"If your needs are less about supporting application-based sending and more around enabling marketing promotion, there are other tools that may be a better fit for you than Postmark."
ActiveCampaign is the opposite. Marketing first. Fingers crossed.