1. Home
  2. Error Message
  3. SMTP
  4. Error 421 Service Unavailable – Causes and Fixes

Error 421 Service Unavailable – Causes and Fixes

Service is unavailable due to a connection problem, please try again later. The message will continuing be attempted for delivery until the connection is restored.

Causes

  • The administrator of the mail server may have stopped the mail server.
  • The administrator of the mail server may have been rebooting the server when you tried to login.
  • Normally indicates a problem with the email server or Internet Service Provider (ISP).

Fixes

Step 1: Remote Mail Server

For user using remote mail server: Make sure that the mail server is functioning properly and connections to it are successful.

Step 2: Destination Server

For user are not using a remote mail server: Check the destination server availability.

Updated on June 22, 2020

Was this article helpful?

Related Articles

Need Help?
Submit a ticket to us and let our professional team assists you

Support Billing Sales
Support
Billing
Sales