Alter Sender email address - WebDav

I have written an applic开发者_如何转开发ation to send an email using the WebDav protocol as shown in the following link. This works perfectly, however there seems to be a limitation that the FROM email address must correspond with the actual exchange user account that the email is sent from.

What I want to know is whether it is possible to set the FROM address to be a miscellaneous email address of my choice, rather than the email address linked to my exchange account like you can do with the SMPT protocol.

In WebDav, you can set the FROM address with any address of users whose "Send On behalf" permission is granted to the email address linked to your exchange account.

i.e If you want to send an email from your exchange account "assistant" on behalf of user "manager", you must first grant "Send On behalf" permission of "manager" account to "assistant" account. To do that, please refer to http://www.msexchange.org/tutorials/Sending-As.html. After that, you can set the FROM address with the address of "manager" account and send email from "assistant" exchange account.

 strText = "From: " & <address of manager> & vbNewLine & _
            "To: " & strTo & vbNewLine & _