Also make sure you read the disclaimer at the end of the post.
This command will provide an export of your Active Directory Schema and export available here: %userprofile% Open with notepad and search for Picture: The line you are interested in is:dn: CN=Picture, CN=Schema, CN=Configuration, DC=contoso, DC=com and under it you have you should have m APIID attribute with value 35998 (I set a wrong value in the screenshot as an example) If the value is not the specified one(35998) you have 2 options: Update the Active Directory Schema to 2008 R2 level following these articles: After this checkpoints Outlook will show the Picture if it is set in Online Mode.
If you decide to deploy Cached Exchange Mode, learn how to Configure Cached Exchange Mode.
Cached Exchange Mode was introduced in Outlook 2003 to give users a seamless online and offline Outlook experience.
Large mailboxes on computers that don’t have sufficient hard disk space for a local copy of the mailbox. For large mailboxes, performance can become an issue in Cached Exchange Mode.