Temporary failure (soft bounce)
Email error 421 4.7.0: Try again later (rate limited or temporarily deferred)
The server is asking you to slow down or come back later. The message is not rejected, it is delayed, and a correctly configured sender retries on its own.
Common causes
- You sent too many messages to that provider in a short time.
- The provider sees unusual traffic from your IP and limits it.
- The server is busy or under maintenance.
- Your sending reputation is low or new.
How to fix it
- Let the mail system retry; do not resend manually in a flood.
- Lower your sending speed and spread large campaigns over several hours.
- Warm up new domains and IPs gradually.
- Clean the list so fewer bounces and complaints lower your reputation.
Clean a whole list · MX lookup · SPF, DKIM and DMARC checker
Frequently asked questions
Will the message be delivered?
Usually yes, if the sender keeps retrying according to its schedule.
How long does it last?
Minutes to a few hours, depending on the provider and your reputation.
Other error codes
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