Microsoft Outlook: Create a new email message from an HTML file

CreateHTMLMsg.bas

Sub CreateHTMLMsg()
 
  Dim sLocation As String
  
  'Change this to the location of your HTML file
  sLocation = "C:\HTML_Template.html"

  Set objMsg = Application.CreateItem(olMailItem)
  Set fso = CreateObject("Scripting.FileSystemObject")
  Set ts = fso.OpenTextFile(sLocation, 1)

  strText = ts.ReadAll
  objMsg.HTMLBody = strText
  objMsg.Display

  'Clear memory
  Set fso = Nothing
  Set ts = Nothing
  Set objMsg = Nothing
    
End Sub