Forum Discussion

JonnyShaw1's avatar
JonnyShaw1
Copper Contributor
Apr 27, 2026

Exchange 2016 Decommission

Hi all,

I am trying to decom my 2016 environment and cannot disable (Disable-Mailbox) the final 16 mailboxes (out of thousands). Am getting the error 

Active directory response: 00002098: SecErr: DSID-03150A45, problem 4003 (INSUFF_ACCESS_RIGHTS), data 0.

I have been troubleshooting this for HOURS now. It's not enabling inheritance on the user perms (every article suggests that). The perm exchange trusted subsystem isn't there. The users do not have any admin groups. It's nothing that I can find in the first 6 pages of googling. Sadly, of course, there is no support anymore so can't even raise a ticket.

Can't uninstall Exchange with mailboxes left :(

Any idea's are more than welcome, please.

Thank you.

2016
admin
Exchange Server

2 Replies

  • AnnTaeYoun's avatar
    AnnTaeYoun
    MVP
    Apr 28, 2026

    JonnyShaw1​ 

    If it is a protected account, use the command below!

    Get-ADUser <User> -Properties adminCount

    Set-ADUser <User> -Replace @{adminCount=0}

    Disable-Mailbox <User>

     

    ADUC -> <User Account> -> Security -> Advanced

    Enable inheritance <Check>

     

    Thanks

    TaeYoun

    • JonnyShaw1's avatar
      JonnyShaw1
      Copper Contributor
      Apr 29, 2026

      Hi,

      Thanks for the reply. It was not a protected account. I had tried all that.

      It is now resolved though through editing the MSexch attributes. Dirty but as doing a decom it doesn't matter :)

      Thanks

      Jon