Question
Why did I get an error message that says "headers too large" when trying to email someone at UC Davis.
Overview
If a message is returned with a non-delivery report (NDR) similar to:
The email system had a problem processing this message. It won't try to deliver this message again.
mx.ucdavis.edu gave this error:
Headers too large (32768 max)
It means the routing information recorded in the email packet has gotten large enough the message can not be properly processed by the receiving email service.
Answer
This is usually caused by a forwarding loop between two or more email addresses. The receiver of the message should check for any rules or forwarding that they might have set up and remove any rules or forwarding to another email address that they may find.
You can check for forwarding within Office365 at https://outlook.office.com/owa/?realm=ucdavis.edu&path=/options/forwarding
You can check for rules and filtering within Office365 at https://outlook.office.com/owa/?realm=ucdavis.edu&path=/options/inboxrules
You can check for rules and filtering within Outlook by clicking on:
- File
- Info
- Rules and Alerts
You can check for forwarding in DavisMail by clicking on:
- The Settings gear symbol
- Settings
- Forwarding and POP/IMAP
You can check for rules and filtering in DavisMail by clicking on:
- The Settings gear symbol
- Settings
- Filters and Blocked Addresses
If you still have questions about the error message please forward the full error message to ithelp@ucdavis.edu