Questions On Crashing, Sluggish, and Configurations

[PinkFloydEffect]

Loaded question I know - but I have several. First off I am using Office 2016 with 4 email accounts.

For years now Outlook will crash if I leave it open for several hours, I seem to be able to avoid it crashing if I refresh the inbox regularly throughout the day but if I let it sit for a few hours it will hang up when updating the folders and never sync. If I close it I am unable to relaunch Outlook, if I expand the taskbar by the clock I will see the Outlook icon greyed out. I then have to open task manager, end Outlook, go back to the task menu icon and hover over it for it to go away THEN relaunch Outlook. This has been going on for years.

It does seem to be getting slower and slower when refreshing the inbox the send/receive tasks can take 30+ seconds. Can I do anything to clean it up? If I view the app data Outlook folder I have 5 data files for 4 email accounts (one is a duplicate) I have tried deleting the duplicate but it regenerates itself upon reopening Outlook. Another data file for one of the email accounts has a (2) in the name, if I remove the (2) it just abandons the file and regenerates another one with the (2) in the name upon reopening Outlook.

The largest two email account data files are around 1GB in size. I like seeing my email accounts case sensitive with some capital letters in Outlook (on the left side menus) so I did edit the data file names years ago with the proper capital letters. However one account is stubborn and if I rename it with caps (not changing the spelling) it does not reflect in Outlook...the email account just remains all lowercase on the left menu. Why would it work for all the others and not one? This is also the account that regenerates a duplicate data file, but I tried editing the name of both the duplicates but it still does not reflect in Outlook.

I am unable to get the email account I want as default set, it used to be the default but now it says "The selected Outlook data file (.pst) format cannot be used. Outlook data files (.pst) must use the same format as offline Outlook data files (.ost) Select a matching Outlook data file (.pst) or turn off cache mode in the Account Settings". If I click the account settings for this email to disable cache mode it says "Your Outlook data file cannot be configured." and shows its directory path with the .ost extension. The confusing thing is all 4 of the email data files ARE .ost and the duplicate one is a .nst

 

[PinkFloydEffect]

Edit/Update: I was able to disable cached exchange mode on one of the duplicate accounts, which deleted the duplicate data file (.nst)

The other 3 accounts do not have an option to uncheck caching, they only have an option not to save copies of sent items. The settings page for them only brings up a dialog to compact the .ost file so I am not sure if this is because they are AOL & GMAIL accounts where the 1 that allowed me to disable cached exchange mode was an Outlook email (using my employers domain). Its the only one with a location as "Online" rather than a local directory.

I deleted all the files in the RoamCache folder, and emptied the Auto-Complete List in Outlook and it seems to sync the folder tasks a bit faster now (still takes around 10-15 seconds on a 200mbps connection).