Can't move arbitration mailbox to another database

Question

I'm trying to delete one database which was the first database we created when we implemented Exchange 2010 , we move all the mailboxes to the new database we created and everything went smooth , also i found that there are some arbitration mailboxes must
be moved too which are
-SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9}
-SystemMailbox{1f05a927-6a10-4cf0-9ca8-fe760801586b}
-FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042
i was able to move the first tow SystemMailboxes with no issue but when i tried to move (Federatedemail) using this command
New-MoveRequest -Identity 'FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042' -TargetDatabase "DB01"
i received this message:
Mailbox size 1.552 MB (1,626,956 bytes) exceeds target quota 1 MB (1,048,576 bytes).
    + CategoryInfo          : InvalidArgument: (FederatedEmail....bf-00a95fa1e042:MailboxOrMailUserIdParameter) [New-M
   oveRequest], RecipientTaskException
    + FullyQualifiedErrorId : CC6C9B00,Microsoft.Exchange.Management.RecipientTasks.NewMoveRequest
Thanks in advance ..

Answer 1

thank you Leif i was able to move the mailbox but i still can't remove the database it got the below error:
Microsoft Exchange Error
The mailbox database 'DB1' cannot be deleted.
DB1
Failed
Error:
This mailbox database contains one or more mailboxes, mailbox plans, archive mailboxes, or arbitration mailboxes. To get a list of all mailboxes in this database, run the command Get-Mailbox -Database <Database ID>. To get a list of all mailbox plans
in this database, run the command Get-MailboxPlan. To get a list of archive mailboxes in this database, run the command Get-Mailbox -Database <Database ID> -Archive. To get a list of all arbitration mailboxes in this database, run the command Get-Mailbox
-Database <Database ID> -Arbitration. To disable a non-arbitration mailbox so that you can delete the mailbox database, run the command Disable-Mailbox <Mailbox ID>. To disable an archive mailbox so you can delete the mailbox database, run the
command Disable-Mailbox <Mailbox ID> -Archive. Arbitration mailboxes should be moved to another server; to do this, run the command New-MoveRequest <parameters>. If this is the last server in the organization, run the command Disable-Mailbox <Mailbox
ID> -Arbitration -DisableLastArbitrationMailboxAllowed to disable the arbitration mailbox. Mailbox plans should be moved to another server; to do this, run the command Set-MailboxPlan <MailboxPlan ID> -Database <Database ID>.
i tried the commands above and it show nothing !!