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How many folders in outlook is too much?  How much ram to deal with that?

BeGentleWithMe-INeedHelp asked
I am a newbie so these may sound like stupidly simple questions.. but they are ones I need to ask.

Working to move a user from hosted exchange to office 365.  He has a PST with 7.5GB of data, about 2000 (2 thousand) folders under the inbox (and some of those are subfolders under the subfolders:

 -> subfolder 1
       -> subfolder A
 -> subfolder 2
 -> subfolder 3

he wants to run outlook 2013 on an i3 laptop with 4GB of ram for this OST.

any of this a red flag?  Not enough ram on the laptop (should ram be > than OST file size, etc?)  Too many folders under inbox (vs. some other folder)

too many folders?
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Director, Practice Manager and Computing Consultant
Awarded 2014
Top Expert 2014
No red flags.
You can have problems if the number of files in a folder exceed about 5,000 - see http://support.microsoft.com/kb/905803
You can be limited by the space you have in your mailbox in Exchange by the administrator.
Obviously, a lot of folders can be hard to manage in itself, but if he's OK with that...
Will SzymkowskiSenior Solution Architect
Most Valuable Expert 2015
Top Expert 2015
With Outlook/Exchange specifically the more emails you have the harder Exchange and Outlook need to work to index search and keep track of all of the emails you have. Using Cached Exchange Mode will increase the performance because the searching is local to the machine as it searches the OST file.

Also take a look at the link below which outlines each verision of Exchagne and the required folder limits to abide by.
Exchange Server Limits

You also need to take into consideration the performance on your Exchange server and how much resources it has and the users it is servicing.

Phillip BurtonDirector, Practice Manager and Computing Consultant
Awarded 2014
Top Expert 2014
Will, but the question isn't about how many emails in each folder, or how many emails in a profile - it's how many folders in a profile.

I note that your link includes the following statement, which seems more to the point:

The creation of more top-level folders, or of subfolders beneath the Inbox and Sent Items folders, greatly reduces the costs that are associated with this index creation
I forgot to mention - there actually aren't many emails in each folder.

but good to know - more folders makes it easier to index?!

Frustrating - trying to push up data from a PST imported into outlook up to office 365.  the bottom of outlook says 'updating [foldername] this folder is up to date.

is it kinda a black box as to how far along it is for pushing all the data?  I am comparing the o365 mailbox size in the admin screens vs. the PST.  4.11GB vs. 7.5GB, so it still has lots to go?
Top Expert 2016

you can't directly compare the 2 technologies i.e. ost size compared to pst size or pst size to mailbox size there is no 1:1 relationship.. the only way is to do a count of the messages in the pst and in the mailbox
david - ok, yeah, I figured numbers wouldn't be exact - sector size, OS, etc.. but  I'm GB apart right now so I know things are missing : )  

 yeah, count the messages would be more accurate.... is there an easy way to do that?  I can right click on folders and see the size in kb for what's in there.  is there a non manual way to count number of messages?

alright, I can have it show number of items, not number of unread items and manually compare things from 1 outlook to another.

would you know what the 'total size', vs. 'size' means in the folder size window?
Top Expert 2016

my outlook pst files when I sent them to office 365 and the size of the mailbox store were also greatly different in size.  you can click on a folder and see the total count of messages
change it from number of unread to number of items
would you know what the 'total size', vs. 'size' means in the folder size window?