COMPARISON
Machine Inbox vs free temp mail.
Free disposable email APIs cost nothing up front. Acceptance is the problem. Known disposable domains sit on public blocklists, and signup fraud filters check those blocklists by default. The filter often rejects the address before any verification email is sent.
SIDE BY SIDE
What the $2.00 changes.
| Dimension | Machine Inbox | Free temp mail APIs |
|---|---|---|
| Price | $0.05 to $2.00 per inbox | Free up front; rejected signups and lost mail are the cost |
| Domain reputation | Private paid-service domain, monitored, not marketed as disposable | Public disposable domains, widely blocklisted |
| Privacy | Private inbox behind a bearer token; deleted at expiry | Often shared or guessable public inboxes |
| Guarantees | Published limits, idempotent purchases, audit trail, operator alerts | Best effort, addresses and domains rotate without notice |
| Replies | Included, to authenticated inbound senders | Rarely supported |
| Verification codes | Dedicated extraction endpoint plus a long-poll wait | Parse the mailbox yourself |
GUIDANCE
Pay when the signup has to succeed.
A rejected signup usually costs more than $0.05: the task fails, the agent retries, the run burns time. Buy the inbox when the address has to be accepted, when the mail has value (documents, receipts, vendor threads), or when the task needs a private address, a reply, or a retention window you control.