Backing Up And Importing Email Accounts For Outlook 2016 In Office 365

Occasional Contributor

I recently cloned my Windows 10 Pro x64 from my factory installed primary drive, which is my OS drive. I cloned it to a new, larger primary OS drive after I formatted the new drive from within my laptop.


I have Office 365 Personal with 27 email accounts, 25 of them being various Microsoft email accounts and 2 of them being POP3 accounts. All the Microsoft email accounts are configured in the same manner and using the same server system. I exceeded the Microsoft limit of 10 email accounts on their Exchange server system by altering the registry to allow the additional accounts (maxnumexchange).

I want to do a reset of my OS, keeping my files in the process. I don't have a problem with reinstalling applications but I don't want to go through the hassle of reconfiguring all 27 of my email accounts in a new installation of Office 365 Personal. I notice that I can export only one of my email accounts at one time using Outlook 2016's export process. Is there any manner in which I can export all 27 email accounts at the same time to the secondary drive in my laptop or to an external drive? I would then import them back into Outlook 2016 after once again making the necessary registry change that allows me more than the ten Microsoft accounts. Perhaps I can skip the registry change after the Windows reset since I already have the 25 Microsoft email accounts configured. I really don't know.

I want to be able to simply import all 27 email accounts at once after the reset is complete and Office 365 Personal has once again been installed.

Thank you in advance for your time and any assistance provided.

4 Replies



In case you are talking about mailbox items within Outlook 2016. 

Then you may find PST file that stores all items within Outlook 2016. So just save PST file on another system or drive. And finally, you can easily restore it back once the system is cleaned 

 Check this post:-

Hope this helps you!!!!

Thank you, gupta, for your prompt reply, and thank you for the link. I appreciate it very much. I found the linked article a couple of days ago. I've been researching this issue for quite some time and it appears that there is no simple solution. I simply want to be able to export or back up all 27 email accounts, preferably at the same time, that I have in Outlook 2016; folders, subfolders, email messages, basically everything, and then be able to import it back into Outlook 2016 once I do the Windows reset and reinstall office 365 Personal.


It's my understanding that I can export only one email account at a time. As far as the export process goes I've read that Outlook 2016 can't import .pst files and I have no idea what comma separated values means. Long story short, I know that I'll do something wrong that will prevent me from moving all these accounts into a newly installed Office 365.


I'm considering purchasing Macrium Reflect. It seems that it can back up the entire Outlook 2016. However, common sense tells me that this isn't going to work because there are probably other folders that I would need to back up so that the Outlook 2016 backup itself will function properly, folders located in Program Files, User Account App Data and other locations. Of course, I could be wrong.


I've also thought about using Macrium Reflect or the Acronis TI 2018 I have to back up all pertinent folders, do the OS reset, delete the pertinent folders in the newly reset OS and then use the backed up pertinent folders in their place but then I realized that I would probably create nothing but unnecessary problems for myself.


Bottom line: I'm almost to the point where I'm simply going to reinstall Office 365, make the necessary registry change (maxnumexchange) and then add all 27 email accounts one at a time. It's a burden nobody should have to suffer but Microsoft doesn't allow third party developers enough access to its Office 365 platform for them to create a simple export/import application.


Thank you again for your time and your assistance.

Problem solved. I'm giving up. I'll add them back to Outlook 2016 one at a time.