If you use Exchange 2003 (I’m not sure if the same applies to later versions), you may have noticed that you cannot set a user’s mailbox size to anything greater than 2097151KB (2GB).
The good news is that this limit is only GUI imposed (soft limit) and not a hard value fixed on the exchange server software it self (hard limit).
Increasing a user’s mailbox is really easy and safe – however, I don’t recommend that you configure the size to some unreasonable or extreme limit.
As always, a full backup of the mail store is recommended before changing any settings on the Exchange.
- Go to Start –> Run
- Type adsiedit.msc
- Go to the container which contains your users
- Right click the user you want to increase the mailbox size for and select Properties
- Edit the values mDBStorageQuota, mDBOverQuotaLimit, mDBOverHardQuotaLimit and mDBUseDefaults
mDBStorageQuota is the value (in KB) in which you want to issue a warning.
mDBOverQuotaLimit is the value (in KB) in which you want to prohibit sending of mail.
mDBOverHardQuotaLimit is the value (in KB) in which you want to prohibit sending and receiving of mail.
mDBUseDefaults (boolean) decides whether the default settings should be used or not. You should set this to False if you have configured the above values and want to use them.
That’s it! The user should now be configured with the new mailbox size.