How can you clean up office365 group mailbox

[Mibalak]

I wanted to clean up a group mailbox which is enabled with send as rights. The mailbox is almost full and there is no easy method to remove all old emails from this group mailbox.

[#2]

You can use retention policies, or some EWS-based script.

[#3]

Thanks Vasil. Are there and documentation available for references.

[#4]

It's covered in the Retention policies documentation: https://docs.microsoft.com/en-us/office365/securitycompliance/retention-policies

[#5]

@Vasil Michev But that refers back to individual maibox. How can this be applied on Group? I dont see this under Recipients->Mailbozes section in Exchange admin center.

[#6]

There's an entire section in the article detailing Group mailboxes, read it: https://docs.microsoft.com/en-us/office365/securitycompliance/retention-policies#office-365-groups-l...

Exchange retention policies do not apply to Groups, you cannot use the EAC for that.

[#7]

@Vasil Michev The Compliance Admin Center, now Microsoft Purview, Policies, Retention heading worked well for this.

Created a policy to purge mail older than 2 years and scoped down to a group, then executed the Start-ManagedFolderAssistant to kick the daemon and it purged mail. Thanks for the pointer.