Keep Postmark. Add independence, not a replacement.
Postmark takes transactional email seriously, and it shows. What no single provider can give you is a second provider, or a record that doesn't live in their account.
If you chose Postmark, you probably chose it on purpose: a provider known for being strict about what it sends. There's rarely a reason to leave. The reasons to add something are narrower: the hour Postmark holds your mail, and the question someone asks after its history window has closed.
That is what Mailway adds in front of the Postmark account you keep. And if neither has ever mattered to you, you probably don't need it.
Strict about the right things.
Transactional and broadcast kept apart
Bulk mail goes through its own Broadcast stream and IP ranges, so a newsletter can't drag down a password reset.
Content kept by default
Message content, events, and metadata are stored for 45 days by default, adjustable from 7 to 365 days with an add-on.
Pauses queue, not drop
If an account crosses its thresholds, sending is paused with messages queued, not thrown away.
Open about incidents
Postmark publishes its incidents on a public status page, including short delivery delays.
What even a careful provider can't do alone.
A pause holds everything
Postmark expects spam complaints under 0.1% and bounces under 10%; an account that crosses them is paused, with messages queued.
source: Postmark: sending limits and pausesQueued mail is accepted mail, so no gateway can reroute what Postmark is holding. What it changes is the next message: move new mail to your second provider with one reorder in the console, while the archive shows exactly what's waiting. Failover needs two providers, so it's available on Pro and up. When Postmark refuses a message instead, the retry goes to the next provider five seconds later.
The history lives in Postmark's account
45 days by default, up to 365 with the retention add-on, which the pricing page offers on Pro plans and higher.
source: Postmark retention add-onYour archive doesn't depend on which provider carried the mail, or on staying with any of them: every message byte-for-byte, for as long as your plan keeps it (a custom window on Enterprise, up to unlimited with a retention add-on), plus signed, independently timestamped proof of delivery on Business and up.
Even the good ones have an hour
Postmark's status page records its incidents openly, including a delivery delay on 2026-09-22 when some messages were held in queue for about 20 minutes.
source: Postmark statusWith a second provider in the chain, a refusal costs seconds. The timeline shows which provider carried each message, so a delay is a fact you can point to rather than a guess.
- Your Postmark account, servers, message streams, pricing, and sender signatures.
- DKIM stays at Postmark. Postmark composes every message it sends itself, over SMTP too: it assigns its own Message-ID and Date and can re-encode the body, so mail through Postmark isn't delivered byte-for-byte and a DKIM signature your app applied won't survive. Mailway hands Postmark your exact bytes and keeps them in the archive.
- Opens and clicks stay in Postmark. Delivered, bounced and complained events come back into Mailway over both transports; SMTP sends are matched through the
X-PM-Metadata-mwheader Mailway adds, which replaces a same-named header your app sets and which Postmark removes before delivery.
If Postmark has never held your mail at a bad moment, 45 days (or 365) of its history answers every question you get, and nobody needs proof of what was sent, Postmark on its own is the right answer. Most Postmark customers are in exactly that position.
Keep Postmark; change one config block.
Add Postmark to Mailway as an SMTP provider with your server API token (mail goes to the server's transactional stream), add a second provider behind it, and point your mailer at smtp.mailway.net with a Mailway SMTP credential (quickstart).
Add a webhook on Postmark's transactional stream with the URL Mailway generates for the provider: it carries credentials Mailway created, and Mailway checks the request comes from Postmark's published addresses, so there is nothing to paste back (Postmark setup).
Keep sending broadcasts through Postmark's Broadcast stream exactly as you do today. Mailway carries your transactional mail; your newsletters don't need to change.
Postmark facts checked 2026 Q3 against the vendor's own pages
- Postmark: how long messages are stored
- Postmark retention add-on
- Postmark: sending limits and pauses
- Postmark: bulk email and message streams
- Postmark SMTP
- Postmark status
- Postmark pricing
Other providers: Amazon SES · SendGrid · Mailgun · all providers
Your mailer config has
one block to change
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