12 September 2025, 01:08 PM
Hello everyone,
Just wanted to share a couple of quick troubleshooting guides for two of the most common (and sometimes frustrating) issues that pop up in Exchange Online. Hope this helps someone save a bit of time!
1. The "Non-Unique Proxy Address" Error
We've all been there. You're trying to update a user or create a new mailbox, and you get hit with the dreaded error about a proxy address already being used. This is especially common in hybrid environments after syncing. Before you start pulling your hair out digging through ADSI Edit, there's a straightforward PowerShell method to pinpoint exactly which object is holding the conflicting address.
I've put together a step-by-step guide on how to quickly find and fix non-unique proxy addresses in Exchange Online:
2. "What Happened to My Email?" - Mastering the Exchange Online Mail Trace
This has to be one of the top questions we get from users. Instead of guessing, the message trace feature in the Exchange Admin Center is your best friend. It gives you a definitive answer on whether an email was delivered, rejected, flagged as spam, or hit a transport rule. Knowing how to run and interpret these traces is a fundamental skill for any EXO admin.
By mastering these two simple procedures, you can knock out a significant number of daily support tickets.
Just wanted to share a couple of quick troubleshooting guides for two of the most common (and sometimes frustrating) issues that pop up in Exchange Online. Hope this helps someone save a bit of time!
1. The "Non-Unique Proxy Address" Error
We've all been there. You're trying to update a user or create a new mailbox, and you get hit with the dreaded error about a proxy address already being used. This is especially common in hybrid environments after syncing. Before you start pulling your hair out digging through ADSI Edit, there's a straightforward PowerShell method to pinpoint exactly which object is holding the conflicting address.
I've put together a step-by-step guide on how to quickly find and fix non-unique proxy addresses in Exchange Online:
2. "What Happened to My Email?" - Mastering the Exchange Online Mail Trace
This has to be one of the top questions we get from users. Instead of guessing, the message trace feature in the Exchange Admin Center is your best friend. It gives you a definitive answer on whether an email was delivered, rejected, flagged as spam, or hit a transport rule. Knowing how to run and interpret these traces is a fundamental skill for any EXO admin.
By mastering these two simple procedures, you can knock out a significant number of daily support tickets.