How to Fix Emails Not Going Through to SBCGlobal.net and ATT.net

There could be several reasons why your emails are not being delivered to SBCGlobal.net and ATT.net addresses. Here are some potential causes and resolutions:

1. Spam Filters: Your emails might be detected as spam. Check if your email content or attachments could be triggering spam filters.
2. Delivery Status: If you are receiving Non-Delivery Reports (NDRs), it could be due to various reasons, including:
   • The message was detected as spam.
   • The message was sent to quarantine due to a rule match.
   • The destination server rejected the message due to aggressive anti-spam settings.
   • The message failed to be delivered because the recipient's email system is unreachable or rejected the message.
3. Email Configuration: Ensure that your email server is correctly configured, including SPF records and other authentication settings. Misconfigured settings can lead to delivery failures.
4. Message Trace: You can run a message trace to find out the status of your emails. This will help you identify if the message was sent, received, filtered, or if there were any delivery failures.
5. Contact Admins: If the issue persists, consider contacting the email administrators of the recipient domains for further assistance. They might provide insights into why your emails are being blocked or bounced.

By investigating these areas, you should be able to identify and resolve the issue with your email delivery to SBCGlobal.net and ATT.net addresses.

References:

• Message Trace FAQ in Exchange Online
• Fix NDR error "550 4.4.7" in Exchange Online