Unable to set send-as permissions because of hundrets of duplicate permissions

Question

hello,
we are unable to set send-as permissons to mailboxes where more than 10 users already habe send-as permissions.
when i use get-adpermission -identity "mailbox_abc" i get 4309 lines with permissions. But most are duplicates. every permission is set 31 times.
when i remove a user there are 4278 lines, when i add an user there are 4309 lines.
it seems that every account has between 1000 and 4000 permission lines
when i use the GUI i only see 10 different permissions
how can i fix it?
thankyou in advance boris

Answer 1

my problem are the hundreds of duplicates
this is the output
Get-ADPermission -Identity "mailbox_abc" | ?{($_.ExtendedRights -like "*send-as*") -and -not ($_.User -like "nt authority\self")} | select identity,user
Identity                                                   
User
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           NT-AUTORITÄT\SELBST
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\gka
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\ma
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\zr
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\fh
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\MT
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           NT-AUTORITÄT\SELBST
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\gka
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\ma
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\zr
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\fh
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\MT
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           NT-AUTORITÄT\SELBST
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\gka
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\ma
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\zr
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\fh
sample.domain/MyBusiness/Users/SBSUsers/sample Mitglied           SAMPLE\MT
alltogether 4300 duplicate lines but only 5 different accounts
rg. borris