The undelivered mail returned to sender – unknown recipient error is telling you that your email couldn’t be delivered to your recipient because the email address you sent it to doesn’t exist or was typed incorrectly.
To fix the undelivered mail returned to sender – unknown recipient error, here are some steps:
1. Check the recipient’s email address: Verify the recipient’s email address. It’s easy to mistype an email address, especially if it’s a long one. Check for any spelling mistakes or incorrect domain names (like “gnail.com” instead of “gmail.com”)
2. Check if the recipient’s mailbox is full: Sometimes this error can get triggered because your recipient’s email mailbox is full. Unfortunately, you can’t fix this problem. The recipient must clear their mailbox to receive new emails. If you can text or call them, let them know their inbox is full and they need to clear it so they can receive email from you.
3. Send to a different email address: If you’ve tried the fixes above and are still getting the error, you might want to consider sending the email to a different email address if the recipient has one.