How to find out how much space an O365 RecipientInbox RulesQuota is consuming?

Question

Good afternoon. When I run Get-Mailbox -Identity %usermailbox% |fl Rulesquota on multiple O365 RecipientMailboxes I get the same value (256KB)

RulesQuota : 256 KB (262,144 bytes)

How do I determine how much space the active Inbox rules are consuming?

Thank you
L

Answer 1

There is no real way to determine that. Its based on the size and complexity of enabled rules not the number:
So one person could have 30 rules and hit the quota and another could have 50.

https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/outlook-on-the-web/increase-the-space-used-by-inbox-rules

Answer 2

Hi @LAR-1968 ,

Agree with Andy that it’s not feasible to check the current utilization size of a user’s Inbox rules.

We might be able get some information about the rule size using the MFCMAPI tool:

1. Follow Step1 to Step11 in this article to locate and highlight the items that have the IPM.Rule.Version2.Message as a “Message Class”.
2. Check the value in the Size filed, which shows the size in Bytes:
   
   But it's quite tedious and the result won't be that reliable. Per my test, some rules are not corvered by the "IPM.Rule.Version2.Message" Message Class and there's no property like the display name which can be used to identify a rule. Moreover, I didn't see any property which seems can indicate whether a rule is enabled or not while the quota for Inbox rules applies only to enabled rules.

So above all, I'd recommend just increase the RulesQuato using the command mentioned in the article shared by Andy when a user is warned that no more rules can be created or updated.

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