Before you compare prices
Cheaper transactional email exists. What it usually does not include is per-customer reputation isolation — on a shared suppression list, one tenant mailing a stale list degrades delivery for every other tenant on the platform, and you will not be able to tell that is what happened.
Common questions
What counts as an email?
One recipient. A message with three addresses in to and one in cc counts as four. Rejected messages do not count.
What happens when I hit a limit?
Sends return daily_quota_exceeded or monthly_quota_exceeded until the window resets — midnight UTC for the day, the 1st for the month. Nothing is queued behind it and nothing is silently dropped, so your retry logic stays in control.
Why two limits?
A daily cap on its own bounds nothing over a month: an account can spend it every day, so a leaked key’s real ceiling is thirty times the number anyone approved. The monthly limit is that second bound. Both are raised on request once you have a delivery history.
Can I send marketing email?
No. This is a transactional API: mail triggered by a user action, addressed to one person. Campaigns need consent management and unsubscribe handling that belongs on a marketing platform. Bulk patterns are detected and will pause your account.
Can I receive mail?
Not through this API — it sends only. Receiving is a separate service with its own pricing.