Does Postmark have an inbox?

No. Postmark receives email and posts it to your app's webhook as JSON, but it has no mailbox for people to read and answer. HelloBox connects to Postmark and gives your team a shared inbox for those messages.

Which Postmark token does HelloBox need?

The Account API token, from Account then API Tokens. HelloBox uses it to read your domains and servers and to set up receiving, and reads the server's own token to send. Your mail keeps going out from your own Postmark account.

Can Postmark receive for more than one domain?

A Postmark server has one inbound domain. In HelloBox, a Postmark connection receives for one domain, which is usually a subdomain like reply.yourdomain.com.

What if HelloBox is down when mail arrives?

Postmark retries the webhook for about ten hours, and HelloBox also asks Postmark to resend mail that failed every attempt. HelloBox only acknowledges an email after saving it.

Is there an inbox for Postmark?

Updated November 11, 2026

Short answer

Postmark can receive email for your domain, but it parses each message and posts it to your app's webhook as JSON. There's no mailbox for people to read and answer. To get one, connect Postmark to HelloBox with an Account API token: it points a server's inbound webhook at HelloBox, stores each email before acknowledging it, and gives your team a shared inbox for hello@ and support@. Your app keeps sending exactly as it does today, and it's free for one person.

How Postmark handles incoming mail

Postmark's inbound processing accepts mail for a domain whose MX record points at inbound.postmarkapp.com, parses it, and posts a JSON document to your webhook: sender, recipients, subject, text and HTML bodies, headers and base64 attachments.

Each Postmark server has one inbound stream and one inbound domain. Postmark recommends a subdomain such as reply.yourdomain.com, so the main domain's mail stays where it is.

The webhook is the only full copy. Postmark doesn't host attachments for you to fetch later, so whatever receives the webhook has to keep the message. If it doesn't answer with a 200, Postmark retries 10 times over about ten hours.

Connect Postmark to HelloBox

In Postmark, open Account then API Tokens and copy the Account API token. Only account owners and admins can see it.
In HelloBox, choose Connect a provider, then Postmark, and paste the token.
Pick a server, or let HelloBox create one named HelloBox (recommended, so its mail and stats stay apart from your app's).
Turn receiving on for one domain. HelloBox shows the MX record, or adds it if your DNS is on Cloudflare.

HelloBox saves every incoming email to its own storage before it tells Postmark the webhook worked, so nothing is lost if anything downstream is slow. Replies go out through your Postmark server, threaded with the original.

What stays the same

Your app's server tokens, SMTP settings and transactional email keep working unchanged.
Postmark bills you for email volume at its own prices. HelloBox plans limit people, domains, storage and contacts, not how much you send.
The token is encrypted before HelloBox stores it. Disconnecting removes the inbound webhook and the delivery webhook it added; your server and domains stay in Postmark.
A server receives for one domain at a time, so a HelloBox connection to Postmark does too.

HelloBox is an independent product and isn't affiliated with Postmark.

Frequently asked questions

Does Postmark have an inbox?: No. Postmark receives email and posts it to your app's webhook as JSON, but it has no mailbox for people to read and answer. HelloBox connects to Postmark and gives your team a shared inbox for those messages.
Which Postmark token does HelloBox need?: The Account API token, from Account then API Tokens. HelloBox uses it to read your domains and servers and to set up receiving, and reads the server's own token to send. Your mail keeps going out from your own Postmark account.
Can Postmark receive for more than one domain?: A Postmark server has one inbound domain. In HelloBox, a Postmark connection receives for one domain, which is usually a subdomain like reply.yourdomain.com.
What if HelloBox is down when mail arrives?: Postmark retries the webhook for about ten hours, and HelloBox also asks Postmark to resend mail that failed every attempt. HelloBox only acknowledges an email after saving it.