1. Check email account settings to make sure there are no restrictions or filters set to block emails from certain addresses.
2. Check the recipient’s email address to ensure that it was entered correctly.
3. Check the recipient’s system and email provider settings for any additional restrictions that may cause incoming emails from your email address to be rejected.
4. Try sending the email from another email address or using a different provider if the same problem persists.
5. If all other methods fail, contact your email provider for further assistance.