OpenEmail against
Postmark
line by line.
Their list price is $15 / month for 10,000 sends, checked in September 2026. Ours counts domains and sends, never people, so set the dials below to your own team and volume.
What they are better at
Deliverability is the whole product. Transactional and broadcast mail travel on separate streams, and its activity and bounce tools are the clearest in the business.
Why people move
Inbound mail arrives as a webhook rather than in a mailbox, and every message past 10,000 a month is billed on top. OpenEmail sends from the address that receives, against an allowance you can see, and your Postmark code keeps working against it.
most mailboxes bill per seat; two or more needs Starter
ours steps at 1, 50 and 500; Proton, HEY, Resend, Fastmail, Postmark and Mailgun charge more
Sending APIs and Mailchimp bill by volume; mailboxes cap it per seat
unlimited on every plan of ours; Proton and Fastmail tie them to seats
Forward EmailTeam
OpenEmailStarter
FastmailBusiness Standard
Google WorkspaceBusiness Starter
SuperhumanStarter + WorkspaceMost of these sell one piece of the job: a mailbox, a sending API, a campaign tool or an app that needs a mailbox from somebody else. The OpenEmail price is the whole job, with mailboxes on your own domains, sending and receiving, the full API and the AI assistant on every plan. So this is not even a fair comparison: every other bar buys one piece, and ours buys all of it.
Line by line.
Postmark is not a mailbox, so it is not on this table. The table compares the places mail actually lands, which is the choice Postmark sits beside rather than replaces.
| Compared | OpenEmail Starter | Fastmail Business Standard | Proton Mail Mail Essentials | Google Workspace Business Starter | HEY for Domains per person | Superhuman Starter + Workspace |
|---|---|---|---|---|---|---|
| What you actually pay for | One plan per workspace | Each person | Each person | Each person | Each person | Each person, twice |
| Five people, every month | $20 | $30 | $39.95 | $42 | $58 | $192 |
| Twentieth person costs | $0 | $6 | $7.99 | $8.40 | $12 | $38.40 |
| Hosts the mail itself | a client on top of Gmail or Outlook | |||||
| Catch-all on your own domain | yours to switch on | paid plans | via a routing rule | aliases; catch-all not documented | whatever the host does | |
| Free on your own domain | one domain, unlimited addresses | trial only | custom domains are paid | trial only | no trial on domains | trial only |
| Drafts, subjects and answers from AI | writing assistant only | Gemini | Business tier | |||
| Your own agent can work the inbox | MCP server | JMAP API | API, no MCP | |||
| End-to-end encryption | between OpenEmail mailboxes | their whole point | enterprise tiers |