With the release of Office 2013 and it's emphasis on OneDrive storage, I've had several people ask about moving their pst file to OneDrive, DropBox and similar services.
The answer: It won't work in most services and is not recommended in any service. Outlook puts a lock on the pst file when the pst file is open. OneDrive (and other cloud solutions) continually syncs the local folder. It won't be able to sync the pst because Outlook has a lock on it and as a result, the pst file could become corrupted and data loss occur.
DropBox does incremental backups (reducing the need to upload a large pst in full each time), however, you need to make sure you close Outlook and wait for all updates to be uploaded before shutting down the computer, otherwise accessing the pst from another computer could result in lost data or a corrupt message store. Always keep a backup copy of the pst. This is an unsupported scenario and Microsoft will not provide support for it.
While you could use OneDrive or another cloud service to store backup copies of your data files, its not recommended due to the large size of many pst files: uploading a large data file can take "forever". If you shut the computer down before its completely uploaded then try to open it from another computer, the pst may be corrupt.
There are online backup services that can backup pst files when Outlook is open and incrementally backup the pst, so only changes are saved. These are safe to use because they are designed to work with Outlook data files. However, unlike backing up a file to OneDrive or DropBox, you can't download the pst file to another computer or when needed. You need to restore it using the backup application.
When you use a backup service I highly recommend verifying the backup several days after setting it up, so your sure it's getting the pst files and also every few months to insure it's still working as expected.
anna says
Hi I uploaded my pst files to one drive, deleted them locally and then my outlook just stopped working and the emails were gone. When I tried restoring/repairing them with SCANPST on outlook it somehow doesn't work and it says the pst data set can't be found in the initial folder, although I put the one drive download of the pst again in the old folder. Please help!
Diane Poremsky says
Did you empty the Recycle bin? It might be better to get the pst files out of the recycle bin.
>>
it says the pst data set can't be found in the initial folder
<< So it says the file can't be found even though you moved the file back from OneDrive? If so, the file may be seriously corrupted. Was it completely synced up to OneDrive before you moved it back? (Or did you make a copy to put in the old folder?)
anna says
I emptied the recycle bin. I downloaded then the file from one drive back to the computer (yes it synced completely before).
Diane Poremsky says
Did you log into onedrive.com and confirm the recycle bin was emptied?
anna says
Yes, unfortunately I emptied the recycle bin.The files synced completely to the cloud and after I noticed that outlook wasn't working, I downloaded the files back from the cloud to the pc and started the SCANPST repairing process that did not work. I don't know if a recovering process with some other software might work..or if there is any other way...
Roland says
Hello,
My harddrive is slow because of low disk space due to huge Outlook Data Files (.pst) from my mailarchive in outlook (2013/ WIN8.1/ POP mail). I moved other files, such as pictures, to OneDrive, but was not successful doing so for the .pst mailarchive (for which I created a seperate archive only, inactive mailaddress to which I moved the archived mailfolders in Outlook). It does not sync to online in OneDrive, so it still uses the same diskspace in the OneDrive folder it seems.
How could I best manage to keep my mailarchive and still free my harddrive space on C? A solution that costs some money, such as a OneDrive or Office upgrade, would be no problem for me, if this would solve this issue. I am unsure and any suggestions are appreciated. Thanks,
Roland
rachana says
OneDrive will not sync due to a file named '.pst' being present in the documents.
Diane Poremsky says
Is the pst file open it outlook? It will error if it's open in outlook, but if its not open and is small enough to sync, it can be stored in onedrive as a backup.
rachana says
I have removed .pst file from onedrive and I have copied to C: user profile. Does this make any issue further?
Diane Poremsky says
That should be fine - anywhere outside of a cloud sync will work.
JohnB says
Digging up this old one again!
I would also like to store my Outlook files in a cloud. Particularly my settings, rules etc. Not particularly my messages because I'm using IMAP.
I use Outlook 365 Windows client and I went looking for my PST file, but I found an OST file instead.
Apparently, the OST file is "... used to save data for offline use and are stored in MS Exchange Server..."
I found my OST file ( .ost) where I'd expect to find my PST file.
Does this mean that my Outlook client automatically synchronises the offline data with the online Exchange Server?
Perhaps I also need to move all my settings files (signatures, personal dictionary, fonts, colours, archives etc. to a cloud to make using Outlook from my laptop and desktop are truly synced?
As an aside, I regularly use MS Access and my files are stored in Dropbox.
I quickly discovered that Dropbox was updating whenever I added or changed some data.
To get around this, I created a batch fie that I use to open access.
- Firstly it stops the Dropbox service then opens Access.
- There is another check to make sure I don't end up with conflicted copies and checks that I haven't got the file open on another machine or that Dropbox updated correctly after the last use.
- When I close access the batch file restarts the Dropbox service and the updated files only sync once.
Diane Poremsky says
>>
Does this mean that my Outlook client automatically synchronises the offline data with the online Exchange Server?
>>
IMAP accounts now use an ost file, not a pst. This allows calendar and contacts in the data file. Because you using imap, you don't need to sync the datafile, but may want to export rules and make a copy of your signature and dictionary.
>>
Perhaps I also need to move all my settings files (signatures, personal dictionary, fonts, colours, archives etc. to a cloud to make using Outlook from my laptop and desktop are truly synced?
>>
I keep copies of some of those files in Dropbox so they are accessible but am not syncing the folders directly. I did that once and have over 200,000 copies of each signature file and folder.
The access tip is good - it won't work for outlook (at least for most people) because outlook is open when the computer is running.
John Steiner says
Hi Diane,
I run a very small business that only nets a maximum of $10,000.00 per year. MS 365 Business is too expensive for me and I technically can't run MS 365 Home since I am running a small home-based business.
Since I periodically travel what would be the best way for me to carry my .pst on the road with me? Do I load it on a flash drive and bring it, or will any of the services work for me when I am travelling? I am the only user of these files so there would not be simultaneous openings and closings of documents or the .pst file.
Thanks,
John
Tim Sowerbutts says
Thank you again for your insightful and useful advice...
Marci says
I have my old outlook pst file but it is very large. I'm instructed by some IT guys to not import but to connect to Outlook 365 and then validate and then move my old pst file to the OneDrive. I've googled how to connect and not import but can't find anything. Any suggestions on how to connect my pst file to my new Outlook 365 without importing the file? Thank You!!
Diane Poremsky says
Don't put it in onedrive. It can go anywhere on your hard drive - just open it in outlook using file, Open, outlook data file or file, account settings, data file tab - click New then select it.
Terry Peters says
Similar question. I use Outlook 2007 on my desktop (WIN 10). I would like to move the pst files (and any other needed files) to my personal cloud drive. Then I could access them from Outlook on my laptop also. Is that possible?
Diane Poremsky says
Using a pst file on a cloud drive is not supported - the cloud drive software will try to sync but can't because outlook has it locked. You would be better off importing it into Outlook.com (on the new server).
Ruumi says
Can anyone advice me how to upload pst files on outlook.com or outlook.app for Mac on the Cloud? I want to use old pst file data to only see the old emails. I won't use the account for any new emails. I have about 5 pst files with around 60GB data. I am using Office 365. I don't have enough disk space on my Mac to import the emails on my Mac. Thanks.
Diane Poremsky says
You'd need to use outlook on a windows computer to import pst files into outlook.com.
Was your outlook.com account migrated to the new server yet? Importing will be easier once it's migrated.
Bas says
Why not use your valuable space in OneDrive by creating an Outlook.com mailbox and configure your Outlook client(s) to use this mailbox through IMAP. All mails you drag/drop into folders in this Outlook.com mailboxes will be available on all your PC's, no need for PST files anymore. You have to be online all the time, but who isn't?
Diane Poremsky says
1. You shouldn't open data files stored in a folder that syncs to a cloud service - it can result in corruption and duplicated files (won't take long to eat up space with a 2GB data file duplicated 100 times.)
2. OneDrive is file storage, not email. You can set outlook.com up as an IMAP account but it will create a local data file and it should not be stored in the onedrive folder. however, if you use outlook.com, setting the account up as an exchange account is better.
Philip Cartledge says
Please see my Reply posted 22nd Jan 2015 for more information, but it seems that my message has not yet got through.
My .pst file (now 406,409 KB) RUNS very successfully from my Dropbox folder on my various devices, and has done for several years. I've NEVER had a problem PROVIDED I make sure that it has updated itself if I'm switching devices (I have 4 devices in my main home). If I hover my mouse over the Dropbox icon in the taskbar, it helpfully tells me "outlook.pst is downloading". Of course I avoid using Outlook on more than the one device here at home. The main use of Dropbox is when I'm at my London flat.
I've no idea about Google Drive, but Dropbox is fantastic because it identifies incremental changes made in the .pst and ONLY makes those changes. Therefore updating is achieved very quickly. Unless OneDrive has recently become more sophisticated, it uploaded and downloaded the entire file each time. In addition Dropbox also enables LAN sync which OneDrive didn't when I experimented with it.
Perhaps someone would be able to tell me whether Google Drive and OneDrive now allow:
1. LAN sync
2. Make only incremental changes
Life would be so much easier if I allowed myself to 'give in' to MS and used OneDrive instead of Dropbox, but until OneDrive is able to do the above, I am forced to stick with Dropbox.
Many thanks
Philip Cartledge
(High Peak, UK)
Diane Poremsky says
It's great that Dropbox now does incremental backup (they didn't when the article was originally written) but it is still risky and you should keep a backup copy of the pst. Just forgetting to close outlook and leaving a computer on before opening outlook on another computer can corrupt it as can shutting outlook and windows down before changes sync up then opening it on another computer.
If something goes wrong, Microsoft won't help - they do not support using cloud services for pst storage.
AFAIK, no, neither onedrive or google drive support LAN sync or incremental changes.
Meg says
Ok after rereading your first sentence above, what if I only back up 1 time a week & close my google drive until I want to back up. When I back up my pst files I'll make sure outlook is closed? Would they still be corrupted?
Diane Poremsky says
As long as it's not to big for google drive, you can keep a copy in it (or any other cloud service). The problem arises when you move a pst there and open it in outlook.
Meg says
Diane,
Can I use google drive as a backup for outlook 2010. It is syncing right now. To restore couldn't I just download the whole pst file from google to somewhere on my c drive & import from outlook? In that process are you saying that I will import a corrupted file? What is the best way to backup outlook?
Diane Poremsky says
As long as it's a copy and outlook isn't using the pst, yes, it can be stored in google drive.
The best backup is to make a copy of the pst.
Flaviu says
I am using Dropbox for more than 2 years with PSTs archive in total of more than 60 GB. How this works is that when outlook is running the sync doesn't work, but when you close the Outlook, Dropbox is doing a change check, and if nothing happens nothing is uploaded, if there are changes, it automatically upload just the differences, even the files are very large, like 5 GB. I have never had any files corrupted, and I want to mention that I am a very heavy email user.
Diane Poremsky says
You are really lucky. It is very risky, especially if you are opening the pst files with multiple versions of Outlook, and is not supported.
Mike Worley says
I'm considering going to Office 365 but have concerns about this issue. As I understand from the Microsoft tech support people, I can move the contents of my pst file to an ost file on the exchange server (one drive?) and then in that way access my mail, contacts, and calendar from multiple computers. Is that correct? My plan is to have 365 on my home PC and on my macbook, and the outlook app on my iPhone and iPad.
Diane Poremsky says
Arte you considering Office 365 Business with an Exchange mailbox or just the Office 2013 software (in the Home subscription)?
Exchange server does not use OneDrive to store email, Outlook.com (formerly Hotmail) does not use OneDrive to store email. At this time, mac won't sync with Outlook.com calendar and contacts. The apps on the devices will sync with either Exchange or Outlook.com.
You can import a pst into an Exchange mailbox; to move mail into Outlook.com, you need to set the account up as an IMAP account to move the mail over. Calendar and contacts need to be exported then import at outlook.com and will sync down to Outlook.
Ruumi says
Refer to the last statement. How does one import pst into Office 365 Home Edition?
Diane Poremsky says
You need to use outlook desktop software to import email into the outlook.com.
George says
My pst file is around 10G and it's stored on a second HD in my pc which makes it really really slow to access. I dont want to go to an SSD solution at the moment, however since i got much space on the cloud (via OneDrive that comes with 365 + Dropbox) can i take advantage of that space in order to make access faster??
Diane Poremsky says
No, you can't move the pst to OneDrive. If you have room on the main drive, you can move the pst to it. That might make it faster.
Greg says
Hi Diane, I currently work through an exchange server based email. I am trying to find out how to link my email to my onedrive account so that all emails are stored on the cloud. I currently work on the basis as mentioned above where I have a .pst folder set up which runs on google drive. I know now that this isn't the best option due to the google drive syncing the whole file on a daily basis (currently sitting at 15Gb and getting bigger). From what I have read it is possible to link up your exchange email to onedrive through office 365. Am I correct and if so can you point me in the right direction in getting this set up?
Diane Poremsky says
No, you can't link Exchange mail to onedrive. You could save it as msg files to the OneDrive folders, but that is not recommended. The only option (and its not a good one) is to have Outlook.com connect to the Exchange mailbox - it'll access the mailbox using POP3.
Is your exchange email not available from the internet?
Roberto Estrada says
Dear Ms. Diane: Good day. I want to move away from PST files. My company has given me a large amount of storage space in my cloud inbox in Outlook - we just migrated to office 365; I am going to create folders and move the contents of the PST files to the inbox. I know the cloud service will back up but for peace of mind: can I back up those folders to my PC?
Diane Poremsky says
You could make regular exports to a local pst to have as a backup, but it's really not necessary. Accidentally Deleted items can be recovered for at least 2 months after the deleted items folder is emptied.
hoytpr says
Worked perfectly. Wonder what those weird entries were that we replaced?
Diane Poremsky says
either Outlook was interrupted writing it or something corrupted it.
Philip Cartledge says
First of all let me come clean upfront because I do NOT run my .pst file from the cloud. But please bear with me and read on, because what I do works.
At Location One my home network consists of two desktop PCs both running Outlook 2013. At Location TWO I have one desktop PC running Outlook 2013. In addition I have a laptop PC which also runs Outlook 2013.
I run dropbox on each of the four computers and my .pst file is stored in D:\dropbox. I can't remember how long I've been using dropbox, but since I'm an enthusiastic 'fools rush in' sort of early adopter, it must be for some years now. Dropbox is able to upload the incremental changes that I've made to the .pst to the cloud. I am, however, careful never to have 2 instances running at the same time, and I'm careful never to shut down the PC before dropbox has finished uploading (not long anyway). My .pst is currently a pretty tidy 326,127 KB. This system works a treat for me and in the years that I've been using dropbox I've never got into a tangle and never had a corruption issue.
More recently I've tried outlook.com but unless I've misremembered, nested folders are not possible & it just doesn't cut the mustard anyway compared with the real thing.
A few years ago, I gave in to the MS hype and decided to try OneDrive instead of dropbox. That was no good at all because OneDrive insisted on uploading and then downloading the entire .pst. It was only at that point that I realised how clever dropbox was. Fibre and cable connections are not available to me and so the experiment was very brief indeed. I might add that OneDrive also lacked LAN sync which is so useful for me when I'm at Location One.
So, Ken Isaacson, try it out and I think you'll soon forget about USB sticks.
Diane Poremsky says
Dropbox is definitely better than OneDrive and with your smallish pst file, it is less of a problem... but I'd still keep a backup copy, just in case....
Joel Bancroft-Connors says
I find it mind boggling that the company that owns and understands best how the PST operates is unable to support its use in a modern Cloud environment. It almost defeats the purpose of Office 365 when one of the most important parts can't be cloud enabled.
There isn't even a way to sync this with Outlook.com?
Diane Poremsky says
The issue is that the pst file was never designed to work over a network - outlook keeps a lock on it. When Outlook was designed nearly 20 years ago, this wasn't an issue. The problem now is that most cloud services can't sync it and even if they could, syncing a multigigabyte file can take forever. Mozy, Carbonite, and a few others that do incremental backups do a better job, although there is always the chance that the pst will be corrupted.
The solution is to use Exchange mailbox (best) or Outlook.com for email if you need to access your mail, calendar, and contacts from multiple computers instead of a pst file and POP3.
Mike Handi says
You referred to some tools that allow an online backup of a pst to a cloud service. I can't seem to find a service like this. Would you have any recommendations?
Diane Poremsky says
You can copy a pst into onedrive, google drive dropbox etc, but you can't open the pst file in outlook while its in the cloud drive. Well, you can, but you risk corruption. If you want to backup files automatically, Mozy and Carbonite are two that can backup outlook files. There are more.
Ken Isaacson says
Diane,
Please tell me if you see a problem with the following: I have two desktops in different locations. I won't be using them "together"-- I'll be weeks at a time at one, and then weeks at a time at the other. When I'm leaving Desktop No. 1, I want to copy the OL pst file (say, to my notebook), travel to Desktop No. 2, and copy the pst file there. When I'm ready to leave Desktop No. 2 and go back to No. 1, copy the pst file and then put it back on No. 1.
The important thing (I think) is that when working on Desktop No. 1, no one will be using Desktop No. 2 (and vice versa), so there's no danger of changes being made to both machines. Only one machine will be used at a time.
This should work, shouldn't it?
Many thanks!
Diane Poremsky says
It should work, yes. If you leave mail on the server, it might redownload mail though.
Joseph McKown says
Diane,
I do not want to copy it to the sky drive... I want it to LIVE on the sky drive. that is where I want to access it like it was on my D drive... What would be the issue with doing that? This way I could access it on my desktop from work, or from my Surface when I am at home. I will never access it from 2 different computers at the same time...
Diane Poremsky says
The pst file can become corrupted very easily. When a file is in skydrive, it tries to sync it every time there is a change and there will be constant changes but Outlook keeps a lock on it, so it can't sync until outlook is closed. If the computer crashes or is shut down too quickly after you close, the updated pst won't be upload to the server or a corrupt copy will be uploaded. Temp files will be uploaded, which can quickly eat up server space. Using Outlook.com (Hotmail) or Office365 (Exchange server) or even an IMAP account is a better, safer option for sharing data between computers.
Jeke says
Thanks for your answer, Diane. Does that also mean a 2010 pst file will work in 2003? I thought they were slightly different in that 2010 contains more info than 2003.
Diane Poremsky says
They are slightly different (but still Unicode format) and yes, they will work - I have not had any problems. If you get any error messages when you try to use a pst with both versions, let me know.
Jeke says
Diane,
I want to put my Outlook 2003 pst file (600MB) on SkyDrive and copy it to another computer using Outlook 2010. Problem is can I use the 2010 version and copy it back to be used in Outlook 2003 as the current pst file? In other words move back and forth between two computers with different versions.
Thanks...
Diane Poremsky says
It will work, as long as you move (or copy) it out of SkyDrive to use it, you can't add it to your profile in the SkyDrive folder.
Jim Wagner says
I found this website that someone is using his skydrive for his pst. I am skeptical.
https://www.guidingtech.com/15216/sync-outlook-email-client-skydrive-multiple-computers/
Diane Poremsky says
You should be skeptical. It won't work. SkyDrive will not sync the pst file while it is open in outlook, only one outlook can be using the pst at one time, it will not sync changes (only the entire data file), and it is limited to 2 GB file size. Finally, sharing a pst file is not going to make it an Exchange server. It just makes the same copy of a pst file on two computers. You can use SkyDrive to backup a pst or copy it to another computer if you want... close outlook, copy the pst file to the skydrive folder. Copy it out of the skydrive folder before using.
Also, his recommendation to move the pst and wait for outlook to complain is likely result in a corrupt profile in Outlook 2007 and up.