How to increase Quota for Outlook Rules on Exchange Server
Outlook stores rules for Exchange accounts on the server to automatically move forwarders or emails online from the Inbox to folders, even if Outlook is not running. The synchronization of rules also offers the advantage when using your own account on another computer. The rules are then automatically downloaded from the server in Outlook.
If many rules are created, or rules with long names are used, the quota storage on the Exchange Server may no longer be sufficient, the default size is limited to 64 KB.
If you try to enable the rules that are disabled, you receive the following error message:
One or more rules couldn’t be uploaded to Exchange server and have been deactivated. This could be because some of the parameters aren’t supported or there’s insufficient space to store all your rules.
The RulesQuota can be extended with the following cmdlet from the Exchange Management Shell.
Set-Mailbox firstname.lastname@example.org -RulesQuota:256kb
Query current RulesQuota with the following cmdlet
Get-Mailbox email@example.com | FL displayname, rulesquota
Note. If rules are created to move to local PST files, advanced options – only on this computer must be enabled. These rules are also uploaded to the server. But they are not run online because PST folders are only present locally on the computer.
Exchange Server Rules Limitation
Microsoft Exchange server, including Office 365 Exchange Online and Outlook.com, as well as on-prem Exchange servers, limit the number of rules a user can have in an Exchange mailbox. The limit is based on total size, not number of rules, so one user might have 20 rules while another has 30.
Exchange 2003 and older limited
Exchange 2003 and older were limited to just 32 KB worth of rules. The limit was increased beginning with Exchange Server 2007, to 64KB by default and configurable up to 256KB. Later versions of Exchange dropped the lower default setting and gave everyone the maximum 256KB. This includes Office 365 Exchange and Outlook.com accounts.