Can't set "TNEFEnabled" attribute at an Exchange 2013 user level or an individual remote domain contact level

Exchange 2013 : Sending a meeting request from Exchange 2013 to GroupWise 2012 or to GW2014 user :

Can't change individual remote user contacts setting for UseMapiRichTextFormat attribute :

I understand you can no longer change this setting in the Exchange Admin Center web site, with Exchange 2010 you could use the

Exchange Management Console.  But with Exchange 2013 you must you Power shell commands to do this now :

1. // For All Mail-Enabled Exchange 2013 users : Disable TNEF :
To do this, for all mail-enabled users, execute the following:

[PS] c:\Windows\System32>Get-MailUser -Resultsize Unlimited | Set-MailUser UseMapiRichTextFormat Never
[PS] c:\Windows\System32>Restart-Service MsExchangeTransport

Result: command executes fine with no error, but I get NO FEEDBACK either...
however, any Exchange user still sends out Rich-Text for appointments, sent from Exchange 2013 OWA.
Don't know what mistake I am making with this command.

2.  // For 1 particular Exchange 2013 user : Disable TNEF :
To do this, for 1 mail-enabled user, execute the following:

[PS] c:\Windows\System32>Set-MailUser "Alias of User" -UseMapiRichTextFormat Never

Result: I get the error: The operation couldn't be performed because object 'Michelle' couldn't be found on
        '<domain>.<subdomain>.<host2>.<host1>.com'.
        + CategoryInfo          : NotSpecified: (:) [Set-MailUser], ManagementObjectNotFoundException
        + FullyQualifiedErrorID : 24FC4DE7,Micrsoft.Exchange.Management.RecipientTasks.SetMailUser
        + PSComputerName        : domain.subdomain.host2.host1.com

NOTE: This user 'Michelle' and 'BPerez' do exist and I can login as these users in OWA fine.  Why the error ?

3.  \\ For remote domain contacts : Enable or disable rich-text setting for recevied meeting requests :
Do this to enable or disable rich-text setting for ALL remote domain contacts :

[PS] c:\Windows\System32>Get-MailContact -Resultsize Unlimited | Set-MailContact -UseMapiRichTextFormat Never <or Always>
[PS] c:\Windows\System32>Restart-Service MsExchangeTransport

Result: command executes fine with no error, however, any remote domain contact still receives Rich-Text for appointments,

sent from Exchange 2013 OWA.  Don't know what mistake I am making with this command.

4.  3.  \\ For 1 particular remote domain contact : Enable or disable rich-text setting for recevied meeting requests : :
Do this to enable or disable rich-text setting for 1 remote domain contact :

[PS] c:\Windows\System32>Set-MailContact "FirstName LastName" -UseMapiRichTextFormat Never <or Always>

Result 1: command executes ok, I guess with the following WARNING in YELLOW: "Warning: The command completed successfully but

no setting of 'subdomain.host2.host1.com/Users/FirstName LastName' have been modified"

[PS] c:\Windows\System32>Restart-Service MsExchangeTransport

Result 2:, however, any remote domain contact still receives Rich-Text for appointments, sent from Exchange 2013 OWA.  Don't

know what mistake I am making with this command.

5.  When I do: [PS] c:\Windows\System32>Get-RemoteDomain -Identity "Default" | Select TNEFEnabled

Result :

  TNEFENabled
  -----------
    True

6.  // To set 1 specific remote domain setting for TNEFEnabled attribute :
       [PS] c:\Windows\System32>Set-RemoteDomain -Identity <remoteDomain1> -TNEFEnabled $false <or true>
       [PS] c:\Windows\System32>Restart-Service MsExchangeTransport

  Result: This Works !, the recipient receives the meeting request as a correctly formatted iCAL appointment in GroupWise

7.  The results above were experienced after I FIRST created the remote domain with :
    [PS] c:\Windows\System32>New-RemoteDomain -Name <Name of external remote domain> -DomainName

8.  When I do: [PS] c:\Windows\System32>Get-RemoteDomain -Identity "remoteDomain1" | Select TNEFEnabled

Result :

  TNEFENabled
  -----------
    True

9.  Bottom line is the only thing that works to set the attribute about Rich-Text is when setting at a general remote domain

level, as described in # 6 above.  I cannot set this attribute successfully at an Exchange user level or an individual remote

domain contact level.  Why ?

I get the same results when sending a meeting request to an external smtp user that is not defined as a registered remote domain contact.  Shows as a mail message rather than iCAL appt.

My understanding is the order of precedence for TNEF conversion settings are:

1.  Outlook settings

2.  Mail user or mail contact settings

3.  Remote domain settings

Thanks,
Bob Perez