I would urge you strongly not to embed video files in e-mail messages. Videos typically feature huge file sizes that are not appropriate to e-mail, and even if Outlook will allow such a file, will tend to irritate recipients while their e-mail servers download the files - especially an issue if they view e-mail on a mobile telephone.
If you want to include video, then put the video somewhere the recipients can access it e.g. dropbox or onedrive and send them a link to the file. The previous code I posted can easily be modified to do that e.g.
Sub SendAttachment(what_address As String, subject_line As String, mail_image As String, video_link As String)
Dim oApp As Object
Dim oEmail As Object
Dim olInsp As Object
Dim wdDoc As Object
Dim oRng As Object
Dim colAttach As Object
Dim oAttach As Object
Dim strLinkText As String
strLinkText = "Click here for video."
Set oApp = CreateObject("Outlook.Application")
Set oEmail = oApp.CreateItem(0)
Set colAttach = oEmail.Attachments
Set oAttach = colAttach.Add(mail_image)
With oEmail
.BodyFormat = 2
Set olInsp = .GetInspector
Set wdDoc = olInsp.WordEditor
Set oRng = wdDoc.Range(0, 0)
oRng.Text = "This is the body text of the message" & vbCr & vbCr & _
"The link appears below this text, and before the default signature." & vbCr & vbCr
oRng.collapse 0
wdDoc.Hyperlinks.Add Anchor:=oRng, _
Address:=video_link, _
SubAddress:="", _
ScreenTip:="", _
TextToDisplay:=strLinkText
.To = what_address
.Subject = subject_line
.Display
'.Send 'resurrect this line after testing.
End With
Set oEmail = Nothing
Set colAttach = Nothing
Set oAttach = Nothing
Set oApp = Nothing
End Sub