Forcing Mail Retention in Exchange Online


Guys, I have been looking around at backup solutions for Exchange online. We are on the M365 E5 license. We are told Exchange Online doesn't offer traditional backup. I wish to be able to restore deleted mail 7 days out (i.e. mail that's been deleted from deleted items). Whilst unlikely a user would do this it's still possible and I need to account for it. Doing some reading though, Exchange Online offers unlimited archiving and hold on all mail as per this link.


So my question is, can a hold be used for this purpose i.e. hold for 7 days? Can folders be restored i.e. folder structure if a user was to delete the folder structure?

3 Replies

Hi @shockotechcom 


By default, Exchange Online keeps permanently deleted items (i.e. deleted out of deleted items) for 14 days by default, but this can be changed to a maximum to 30 days - this is for all mailboxes.


In terms of backup - what kind of backup are you looking for? You may want to focus in on Retention Policies if there is certain data you want to ensure is not deleted; alternatively, there are some third party services that act as a more traditional backup.

Look into Retention Policies:

If you have the right licensing E3, Exchange Plan 2 etc. you can easily setup a policy for all mailboxes to retain all e-mail for a set amount of time. 7 Years in my case. It's a few clicks and works great. You can restore e-mail from e-discovery or powershell methods when accounts get deleted any point in that set timeframe and import into other mailboxes etc. No need for Backup solution IMO. is the admin interface for setting it up, you can also set for SharePoint and other services, but they do have a few caviots when it comes to deleting folders that aren't empty once turned on etc. But anyway, look into the article, this should get you going.

Thanks for the reply @Chris Webb . I'm new to O365. Do retention policies prevent users deleting mail though? Also, do they protect against malware corrupting mail i.e. is the mail immutable?