mailgun account probation

"Account probation" is not an SMTP reply code or RFC status — it is a Mailgun account state. Mailgun places new accounts, and accounts its automated systems flag as suspicious, on probation. While on probation your account is partially limited: a common cap is 100 messages per hour per domain, and some features are restricted. Probation stays in place until you complete Business Verification and Mailgun's team approves it.

What causes Mailgun account probation?

There are two distinct triggers people lump under "probation," and the fix differs:

• New / automatically-flagged account (true probation). Mailgun's automated systems evaluate signup and early-sending signals and place the account on probation pending Business Verification. Per Mailgun, "until business verification is completed, the account will remain on probation, which means sending and the account as a whole will be partially limited." This is the core meaning of the term.
• Reputation damage on a sending domain. Separately, Mailgun will temporarily disable a domain if it crosses reputation thresholds — Mailgun's documented limits are a bounce rate above 5% or a spam-complaint rate above 0.05%. This is a domain-level disable, not account probation, but it produces a similar "you can't send" symptom.

Knowing which one you're hitting matters: verification fixes probation; cleaning your list and contacting support fixes a disabled domain.

How do I get my Mailgun account off probation?

1. Complete Business Verification. In the Mailgun Control Panel, open the Business Verification form (Mailgun KB 202850080). It asks about your business, use case, and sending volume. Submitting it opens a support ticket; the confirmation page gives an expected decision timeline. Probation is removed once Mailgun approves the verification — there is no way to bypass it by sending more. The hourly sending cap that applies while you wait is documented separately (Mailgun KB 115001124753).
2. Keep sending clean traffic while you wait. Send only to addresses that opted in. Good early traffic helps Mailgun raise limits; high bounces or complaints will keep you flagged.
3. If a domain was disabled for bounces/complaints, clean up first, then contact support. Review your logs and Suppressions list (Bounces, Complaints, Unsubscribes). Remove invalid addresses from your mailing list at the source — do not just delete a suppression and resend, because re-sending to a known-bad address damages reputation more than the original bounce. After fixing the list, contact Mailgun support to re-enable the domain.

How do I avoid getting re-flagged?

• Stay under the thresholds: bounce rate < 5%, complaint rate < 0.05%.
• Validate addresses at signup (e.g., Mailgun's email validation) and use confirmed opt-in so spam traps and typos never enter your list.
• Honor the suppression list — it exists to stop sending to addresses that already bounced or complained; leave those entries in place.
• Warm up gradually. New senders start with low automatic rates that increase as reputation builds; don't try to blast a large list on day one.

If you send through Courier with Mailgun as your provider, the same rules apply — probation and domain disables happen at the Mailgun account/domain level, so resolve them in the Mailgun Control Panel, then resume sending through Courier.