Private Declare Function ShellExecute Lib "shell32" Alias "ShellExecuteA" _
                (ByVal hwnd As Long, _
                ByVal lpOperation As String, _
                ByVal lpFile As String, _
                ByVal lpParameters As String, _
                ByVal lpDirectory As String, _
                ByVal nShowCmd As Long) As Long
                
Private Const SW_SHOWNORMAL =  1 

Public Sub MailTo(ByVal MailTo As String)
    ShellExecute  0 , vbNullString, MailTo, vbNullString, vbNullString, SW_SHOWNORMAL
End Sub
 
Public Sub test()
    MailTo "mailto:me@domain.com?subject=тест"
End Sub