Common Reasons Your Email Was Not Delivered

 Problem

You received an automated message that an email you sent could not be delivered, or that your email account is currently blocked from sending email.

 Solution

There are several reasons this might be the case. The automated notification you receive from Microsoft 365 will have details as to why, though the explanation in the message may be highly technical and difficult to understand. Some common reasons include:

1. The email address you are sending to may not be valid. This sometimes happens because an old/invalid email address is being auto-completed when you start typing in the To: field of the message. Microsoft provides more information on how you can resolve that issue here: Manage suggested recipients in the To, Cc, and Bcc boxes with Auto-Complete (microsoft.com).

2. Your email may have been blocked by the recipient’s email system, if you are sending email to an address other than an @wwu.edu address. Popular mail providers like Google and Microsoft enforce their own rules for spam and junk mail filtering, and WWU cannot guarantee that a message will be delivered once it leaves the WWU mail system.

3. You may have exceed the student email sending limit. Western imposes limits on how many emails a student account can send per hour and per day, to prevent compromised accounts from being used to spam others. This restriction also applies to employees who have a student status in Banner, either because they are taking a class, admitted to a graduate program, or due to a data entry error. Employees who have a student status can be exempted from the student email limit by contacting the ATUS Help Desk. Students who exceed the sending limit will be automatically blocked for 24 hours, and there is no way to unblock the account before the 24 hour period expires.

4. You may have exceeded the Microsoft 365 service limits for sending email. These limits are enforced by Microsoft on all customers, including Western, and there is no exception process. Microsoft publishes their service limits here: Exchange Online limits - Service Descriptions | Microsoft Docs.

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