As a B2B SaaS, our opportunity cost for support (and potential for lost goodwill) due to failed notifications is high, and switching to Postmark noticeably moved the needle. Time is our most valuable and scarce resource, and peer recommendation is our primary marketing device, so the price increment for switching to Postmark is easily justified. Their deliverability and support are stellar compared to Sendgrid, Mailgun, and SES.

Two thumbs up

See also: Fastmail over G suite for your mailboxes and calendaring.

I do wish they would let you choose the region where the server is located though, like Mailgun does.