Unable to get Microsoft Outlook Account using VBA

Question

I am trying to get Emails from a folder in Microsoft Outlook from a VBA module in Microsoft Outlook. This just fine for one of my accounts, but not for another.

Only one account is available when I set the namespace object, even though I can see three in Outlook.

Any ideas why some accounts would not show up would be appreciated.

Public Function get_Outlook_Account_By_Name(strMailboxName As String) As outlook.Account
    Dim olApp As outlook.application
    Dim olNamespace As outlook.NameSpace
    Dim olAccount As outlook.Account
    
    Set olApp = New outlook.application
    Set olNamespace = olApp.GetNamespace("MAPI")
    
    For Each olAccount In olNamespace.Accounts
        If olAccount.DisplayName = strMailboxName Then
            Set get_Outlook_Account_By_Name = olAccount
            Exit For
        End If
    Next olAccount
    
    Set olApp = Nothing
    Set olNamespace = Nothing
End Function