I've done quite a bit of searching and haven't been able to find an answer to this question. Does Exchange 2007 store OWA auto-complete entries indefinately or will it get rid of them eventually? (60-90 days?). I had a user ask me why autocompletes for customers disappear after a while. I decided to test this and went to my machine to see if it would auto complete an email address for someone I haven't emailed since September 2010 and was in fact not there. ( PLENTY of emails were sent to this email address). Any help would be appreciated. Thanks -

Looks like the auto complete addresses limit is hard coded to 100 and any addresses which are not used much are deleted from the cache. Please check the post below for more information. http://social.technet.microsoft.com/Forums/en-US/exchangesvrclients/thread/8dc94255-e485-437a-b114-1245d8a2c53a/

Hi, Yes, the limitation for OWA auto-complete entries is 100. Then it will save the new address and drop the oldest one. Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT