I just opened an Office 365 Small Business account and imported email dating back to 2001 (26,660 messages in my inbox but under 3 GB of total space used in my mailbox).
When I use Outlook Web App in Firefox or Chrome, or use Outlook 2013 I can scroll to the bottom of my mailbox and see all messages. However, in IE 9 and 10 I only see messages dating back to about 2005. If I re-sort my mailbox to sort with Oldest first, I see the old messages, but nothing newer than 2012. It seems like IE can only display a certain number of messages.
I'm using my personal account as a test for my company. If people can't see all of their messages, we may not migrate into Office 365.
I was just on the phone with MSFT Support. He had me reset IE, Clear my cache, cookies, & History, increase my Cache size, try IE 9 & 10 on different computers. None of it helped.
Has anyone else run into this before?