Outlook freezing up, probably due to large mailboxes

Copper Contributor



I was wondering if anyone can advise us on the following, our customer has quite some shared mailboxes, some of which contain 40-50 GB of e-mail. This on itself is not a problem, since they moved to Exchange online they are experiencing hangs, Outlook freezing up when searching etc.

We tried only caching 1 year of e-mails, Outlook in online mode, however the problems keep returning.


I was wondering what would be advisable, using Exchange online archiving, archiving the e-mails to a PST file or maybe something else?


Thanks in advance.

1 Reply

Use the Online archive, bring down the size of the main mailbox to something more manageable, combine it with the cache slider settings to make sure the local OST file stays below 10GB or so (that depends on too many factors, the idea is try to keep it as small as possible). Better yet, only open the shared mailboxes on demand, via OWA.