"ERROR: [7559-1-221-00000000]PowerShell Error: AdFwd::_PSHEnableObject() - PowerShell Result: Error" (4212250)

You perform a provision process and you see the following error:

20:08:24 ERROR: [7559-1-221-00000000]PowerShell Error:
20:08:24 AdFwd::_PSHEnableObject() - PowerShell Result: ErrorId: 87FA161B
20:08:24 Error: The proxy address "SMTP:first.last@domain.com" is already being used by "ad.domain.local/Accounts/Domain/Contacts/Domino/First Last\/ABC\/Domain". Please choose another proxy address.
20:08:24 ERROR: [7437-1-196-00000000]Unable to enable object. Reason:  'ErrorId: 87FA161B
20:08:24 Error: The proxy address "SMTP:first.last@domain.com" is already being used by ""ad.domain.local/Accounts/domain/Contacts/Domino/First Last\/ABC\/Domain". Please choose another proxy address.

WORKAORUND

1- Open Global Default Settings (INI file)

2- Find [ActiveDirectory] section

3- Add the following:

• MailEnableAttempts=4
• MailEnableRetryWaitSeconds=40
• PSRetryAttempts=4
• PSRetryWait=20
  

4- Save INI file

Above parameter values shall be increase to  values that may suit better for your environment.