For those of you who use Exchange Online 365 and Outlook for your day-to-day messaging needs, you may have found a cap of 128k worth of rules that can be processed. This size comes from the size of the Outlook .rwz file which holds your Outlook rules. As you start to create additional rules, the size of this file will grow and once you have reached ~128k, any rules created after that will not fire/work. To reduce the size of this file and by extension be able to run a larger amount of rules, you can use the following approach, which significantly reduces the size of the rules, which mean more rules can be created and used:
- When creating Outlook rules, when prompted to browse to select a user alias/DL, etc MANUALLY type the alias
- When you browse and select a user/group, the entire Distinguished Name (DN) is used and populated into the .rwz file, which significantly increases the file size, thus limiting the amount of entries you can have/use.