Hosted exchange uses a .ost if it is setup as "Cached Exchange Mode"
IMAP and exchange are different ways to sync. IMAP is basically just "live email" and exchange is live email plus synced calendar, contacts, tasks,
etc....
IMAP will always be delivered to a pst using outlook.
IMAP will not sync sent mail across devices. --- big issue to some.
Basically he wants the emails synced to his desktop PC so he has actual copies "offline" - so even though it's imap he can use outlook desktop to look
back at old emails, even if he's disconnected.
He had that ability with google apps and should have that ability with any IMAP server or hosted/on premises exchange. Not sure why one could not
previous it is how it has been done since Office 2003.
Of course files may still get corrupt. Probably will happen to the exec who has 6 gigs of deleted email still in his box. The host won't make a
difference. How the host deals with problems is the issue. Who would you rather work with, Google with their infrastructure in place or the 3rd
party IT shop who takes 4 days to fix email while trying to steal business?
It sounds like the third party is trying to get a piece of google's pie.
The sad user sounds like he was setup using POP3 if had complaints about sync issues.
There are two types of Outlook Data Files used by Outlook. An Outlook Data File (.pst) is used for most accounts. If you are using a Microsoft
Exchange account, your items are usually delivered to and saved on the mail server. To allow you to work with your messages even when you can’t
connect to the mail server, a second type of data file that is named an offline Outlook Data File (.ost) is kept on your computer.
The primary differences between the two types of Outlook data files are as follows:
Outlook Data Files (.pst) are used for POP3, IMAP, and web-based mail accounts. When you want to create archives or back up your Outlook folders and
items on your computer, such as Exchange accounts, you must create and use additional .pst files.
Outlook Data Files (.ost) are used when you have an Exchange account and want to work offline or use or use the default Cached Exchange Mode. This
type of data file is also used for accounts that you set up with the Outlook Connector for Outlook.com (formerly Hotmail). Outlook Data Files (.ost)
are always copies of items that are saved on a mail server and don’t have to be backed up like Outlook Data Files (.pst).
edit on 9/24/2016 by staple because: this site is messing with my post
edit on 9.24.2016 by Kandinsky because: (no reason
given)