Moving mailbox Error - Exchange 2013 to Exchange 2019

Question

Hello, I am trying to move mailbox from Exchange 2013 to 2019. One particular mailbox throws me following error while I tried to move it. None of the other mailbox has any such issue and worked very well. Note: At very first, while moving mailbox named "accounts", I had a space issue on Exchange2016 (Destination) and hence I have to cancel the migration of this mailbox. I did it by shell command as well EAC. But then whenever I try to migrate the same mailbox again, it throws me an error for this mailbox only.

[PS] C:\Windows\system32>
New-MoveRequest "accounts" -TargetDatabase "Mailbox Database xxxxxxxx"
Cannot open mailbox /o=xxxxxxx/ou=Exchange Administrative Group
(FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=EX2/cn=Microsoft System Attendant.
    + CategoryInfo          : NotSpecified: (:) [New-MoveRequest], RemoteTransientException
    + FullyQualifiedErrorId : [Server=MAIL1,RequestId=325262a1-e055-4812-9833-077badb50261,TimeStamp=4/17/2023 5:34:17
    AM] [FailureCategory=Cmdlet-RemoteTransientException] 66F6F8F,Microsoft.Exchange.Management.RecipientTasks.NewMov
  eRequest
    + PSComputerName        : mail1.xxxxxxxxx.local

Answer 1

Hi @SenkP ,

• Please follow the steps below to check if the migration arbitration mailbox is running fine:

1. Run the following cmdlet to find out the database which is hosting the Migration arbitration mailbox: Get-Mailbox -Arbitration | FL NAME,DATABASE
2. Run the cmdlet below to check the status of the database: Get-MailboxDatabase -Status | fl name,mounted
3. If the database is dismounted, please mount it back and try again to see the result. Here is a similar thread for your reference: Error while moving mailbox from 2010 to 2016.

• Since the issue above is related to the System Attendant mailbox, you can try recreating the migration arbitration mailbox and verify the result again. Step reference: Re-create the Microsoft Exchange Migration mailbox. Tip of The Day: System Attendant Mailbox and Exchange 2013.

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