Cannot recover inactive mailbox

[Grzegorz Wierzbicki]

Hi

I have some inactive mailboxes I need to recover.

I am running into proxy address conflict when running New-Mailbox -InactiveMailbox cmdlet.

The conflict is for SPO: address and apparently my mailboxes are conflicting with "Microsoft Exchange Approval Assistant".

I do not see any conflict resolution options that could be used with New-Mailbox.

Cmdlet error with following error message:
Microsoft.Exchange.Configuration.ObjectModel.ProxyAddressExistsException: The proxy address
"SPO:SPO_dea94f4a-33d9-45ca-98b8-3a74263bcedb@SPO_372ee9e0-9ce0-4033-a64a-c07073a91ecd" is already being used by the proxy addresses or LegacyExchangeDN of
"SPO_Arbitration_dea94f4a-33d9-45ca-98b8-3a74263bcedb". Please choose another proxy address. ---> System.Exception: ( The "UserMailbox" with display name "Microsoft
Exchange Approval Assistant" is already setup and using the same address.)

[#2]

You can always provision a new mailbox, use the "restore" operation to copy the content of the inactive mailbox there, then populate the attributes manually. 

[#3]

@Grzegorz Wierzbicki Did you managed to get the fix ?

I am also facing similar issue while recovering an Inactive mailbox.

The suggestion given by @Vasil Michev simply does not meet my requirement so don't want to restore the mailbox 

[#4]

@aanandkarki 

No, I did not.

I moved to other things and didn't dig into this one

[#5]

Did you try reconnecting a disconnected Mailbox to a new Account?
Recreate the deleted Account and Enable-Mailbox to the "new" Account.