Modify Sender (or From address) of EmailMessage using EWS API

Hi,

I am trying to modify Sender (or From address) of public folder items. Though Sender and From properties are writable according to this document:

https://msdn.microsoft.com/en-us/library/office/dn600367(v=exchg.150).aspx

but EWS API is throwing error when I am trying to modify these properties.

When I am trying to modify 'From' field of email item, i m getting this error:

Exception: Message is not draft.

When I am trying to modify 'Sender' field of email item, i m getting this error:

Exception: This property can't be updated.

I also tested this with email items in Inbox folder of a mailbox, and faced same errors.

This is piece of code, I am using

foreach (Item item in findResults.Items)
{
   EmailMessage msg = item as EmailMessage;
  msg.Sender = new  EmailAddress("jt@mydomain.onmicrosoft.com");
//Also tried
//  msg.From= new  EmailAddress("jt@mydomain.onmicrosoft.com");
  msg.Update(ConflictResolutionMode.AutoResolve);

 }

I am looking to find out some substitute method for this. Can anyone help.

Thanks in anticipation.

Regards, David Johnson