Which to do depends on how large your Exchange storage limit is.If you have a generous Exchange storage allocation, you can probably do number 2 and spread your mail across multiple Processed Mail folders on the server (just alter the names to indicate the date range).Nearly all my books and classes discuss the huge benefits of doing this, so I won’t repeat the reasons here (for more online information about how I use the Processed Mail folder, see this article). Microsoft has an article on this and it states the limit is directly determined by the version of your Exchange Server.
Or, if available, start using the new Personal Archives feature that some companies are slowly starting to roll out with their Exchange 2010; that will solve the issue too.
That means Exchange Server 2010 has pretty much eliminated the problem since most users will probably hit their mailbox storage size limit well before reaching 100,000 items in one folder.
Again, you have to contact your IT department to find out your Exchange version.
It’s a bit ironic that a filing best-practice that will make you more productive could lead to a technical server issue. That’s not a lot of mail and so that number will be easy to reach if your company is using those older versions of Exchange and you are filing a lot of mail in one folder. Links at the bottom of the article I referenced above lead to other articles that state their limits.
And even if you are not using the Processed Mail folder approach, but perhaps you are storing lots of old mail in your , then you could still be impacted by this issue; the Inbox is subject to the same limits. Apparently Exchange Server 2007 has a single-folder count limit of around 20,000 items; and Exchange Server 2010 has a limit of around 100,000 items.
If so, you may have a problem that most people are not aware of: you may have reached Exchange’s , not size, and that count is not that hard to reach well before you run out of mailbox storage space.