Two (both different) Out of Office (OOF) messages are sent to the recipients when you expect only one.
A user sets up an Out of Office message using Outlook desktop client or Webmail and when a sender sends them an email, they receive two separate OOF responses.
This is a very unusual problem but since I’ve witnessed this many times and the endless hours of research I had to put in to figure out, calls for an article on its own.
Don’t confuse this with the Microsoft’s article which has been published under a similar title here: https://support.microsoft.com/en-us/help/3106609/out-of-office-oof-messages-are-sent-multiple-times-to-recipients
This can only be resolved one way; someone needs to have access to user’s Outlook client or have Full access on their account; so can be configured as a Shared mailbox using Outlook desktop client(configuration on existing Outlook profile won’t work):
- Launch Outlook client
- Click on File > Automatic Replies > A new window will popup
- On the lower left corner, click Rules. Another window will appear
- You will find rule(s) here, pertaining to the second(mostly outdated) OOF response that is being sent out against incoming emails
- Delete these rules
A few pointers to note:
- These rules are completely different than the ones we have in Outlook which are used to define certain actions for all incoming and outgoing emails
- These rules are not available through Webmail due to its limited capabilities
- Sole purpose of these are to act against incoming emails towards responding to the sender