If the nickname cache is corrupted, Outlook may be unable to identify recipients, may offer incorrect recipients when automatically completing the email address, or may send the message to the wrong person.
Unlike earlier versions of Outlook that store the nickname cache in a file on your computer, Outlook 2010 stores the nickname cache in your primary message store.
Since I found out about Outlook's "Cached Exchange Mode" I've been using it, and I also set it up on every PC I come across.
In this guide, the relevant timings are explained and instructions are given in how you can directly force an update and resync, which can be very handy when troubleshooting or when you work in an Exchange environment which sees a lot of user mailbox mutations.If you want to store your email locally to view often I would back them up to a PST.With PSTs not only can you password protect your data (if you so wish) and but also keep it with you on a flash drive or the like (consistent backups are a must! If your PST is growing close to 20 GB I would recommend making a second one to store more recent or a more specific set of data, e.g., funnycatpictures.pst, receiptsofclientorders.pst, as past 20 GB PSTs become unstable and are prone to corruption, unless you are using MS Office 2010 or later where the limit is 50 GB.There’s lots of interesting aspects to explore about Office 365 Groups, including the recent arrival of support in Outlook 2016, which is the focus of this article.Outlook 2016 is part of the Outlook 2016 suite and is currently available as a preview edition.This means that in the worst possible scenario, an update to the Address Book won’t become available to the user until 48 hours after the change.