Retrying form submissions that failed to reach your CRM

Which failures to retry

• Retry: timeouts, 5xx errors, an HTML error page instead of JSON, 429 “slow down”, and 401 or 403 — a broken key gets fixed, and then the entries should follow.
• Don't retry: an address the service rejects as invalid, or a contact who unsubscribed. The answer won't change, and repeating it can look like abuse.

Mailbag Pro's schedule

In Mailbag Pro, the paid add-on to Mailbag Contact Form, a failed delivery is tried again after 5 minutes, 30 minutes, 2 hours, 12 hours and 24 hours, then once a day. After 7 days it's marked failed and waits for you to resend it by hand from the entry. If a service says how long to wait — a 429 with a Retry-After header — Pro waits that long instead.

Where the queue lives, and what runs it

The queue is a table of its own that points to the saved entry, rather than a copy of the entry's data — deleting the entry removes it from the queue too. It doesn't rely on WP-Cron, which only runs when the site has visitors and is switched off on many servers. Instead, deliveries that are due go out after the next form submission, or when an administrator opens the dashboard; each run does a few and stops within a time limit, so neither visitors nor admins wait.

One broken connection, not many alerts

When a connection fails, Pro emails you at most once a day about it, and once more when it works again, with how many entries it delivered from the queue. You can see each entry's state — sent, retrying, refused — on the entry itself.

See Mailbag Pro for what it costs.