Send from another email address in Outlook - vba

Question

My users have their personal mailbox as their primary account and an auto-mapped shared mailbox configured in their Outlook 2010 client. The shared mailbox is an Office 365 shared mailbox and thus cannot be logged into to set it as the primary account.
I am trying to start a new email from the shared account's address.
Below is the VBA code I have been trying to use. I have allowed Macros in Outlook's trust center settings.
Public Sub New_Mail()
Dim oAccount As Outlook.Account
Dim oMail As Outlook.MailItem
For Each oAccount In Application.Session.Accounts
If oAccount = "sharedMailboxAddress#domain.tld" Then
Set oMail = Application.CreateItem(olMailItem)
oMail.SendUsingAccount = oAccount
oMail.Display
End If
Next
End Sub

Answer 1

Using the following code with the SentOnBehalfOfName property starts a new email from the shared mailbox's address. Thanks to Dmitry Streblechenko for pointing me in the right direction.
Sub New_Mail()
Dim objMsg As MailItem
Set objMsg = Application.CreateItem(olMailItem)
With objMsg
.SentOnBehalfOfName = "sharedMailboxAddress#domain.tld"
.Display
End With
Set objMsg = Nothing
End Sub

Answer 2

A delegate mailbox will not be in the Namespace.Accounts list.
Set the MailItem.SentOnBehalfOfName property instead.

Answer 3

What does not work in your code?
Use the smtpAddress property to select an account.
Example function:
Private Function GetAccountForEmailAddress(smtpAddress As String) As Outlook.account
Dim account As Outlook.account
For Each account In Application.Session.accounts
If LCase(account.smtpAddress) = LCase(smtpAddress) Then
Set GetAccountForEmailAddress = account
Exit Function
End If
Next account
MsgBox "No Account with SmtpAddress: " & smtpAddress & " exists!", vbCritical, "Oops!"
Set GetAccountForEmailAddress = Nothing
End Function

Answer 4

The debug.print line will show you the accounts.
Option Explicit
Public Sub New_Mail()
Dim oAccount As account
Dim oMail As mailItem
For Each oAccount In Session.Accounts
Debug.Print oAccount
If LCase(oAccount) = LCase("text copied from the immediate window") Then
Set oMail = CreateItem(olMailItem)
oMail.SendUsingAccount = oAccount
oMail.Display
End If
Next
ExitRoutine:
Set oMail = Nothing
End Sub

Answer 5

Not exactly the problem I had, but this question and the answers helped. My problem was to send from a particular mailbox while using many accounts. The one-liner answer was this:
OutMail.SendUsingAccount = OutApp.Session.Accounts.Item("address#domain.com")