Send workbook via email to multiple recipients

I am using the following code to try and send a workbook via attachment to multiple email recipients however it will not work. If I only include one recipient then the code runs fine however it crashes when there is more than one.

I get runtime error '1004': Unknown recipient name found in recipient list. Use a valid name and try again.

Is anyone able to help me?

Sub Mail_Workbook_1()
Dim myFile As String
Dim myMsg As String
Dim myEmail As String 'MsgBox ActiveWorkbook.Name
myFile = ActiveWorkbook.Name
myMsg = "Submitted sheet"
myEmail = "aa@bc.org.uk;bb@bc.org.uk"
Application.Workbooks(myFile).SendMail myEmail, myMsg, False
End Sub

Have you looked here?

http://www.rondebruin.nl/win/s1/outlook/amail1.htm

From what i can gather, this should work but it will send the latest saved version of the workbook.

Sub Mail_workbook_Outlook_1()
    Dim OutApp As Object
    Dim OutMail As Object

    Set OutApp = CreateObject("Outlook.Application")
    Set OutMail = OutApp.CreateItem(0)

    On Error Resume Next
    With OutMail
        .to = "aa@bc.org.uk; bb@bc.org.uk"
        .CC = ""
        .BCC = ""
        .Subject = "This is the Subject line"
        .Body = "Submitted sheet"
        .Attachments.Add ActiveWorkbook.FullName
        .Display   'or use .Send
    End With
    On Error GoTo 0

    Set OutMail = Nothing
    Set OutApp = Nothing
End Sub

The emails now work but the workbooks attached to the emails are blank! Does the user need to save the workbook before they submit the workbook?

Yes, the user has to save the workbook at least once.

Brill. It works great now!
What I would like now is for a confirmation message to pop up after the user clicks submit (to stop me receiving 3 emails all with the same workbook)! I'm new to all this so any help is gratefully received!

Sorry but I'm not sure what you mean. What do you want the pop up to display and what do you want to trigger it?

Sorry, not making myself clear.
Once the user clicks on the submit button, an email will send the workbook through. But as there is no message the user is sending it 3 times as they don't know if it's sent! I'd like a message/comment to display after they click on the "submit" to say something like "your workbook has been sent".
Many Thanks for this

Thanks for this. I will try the code and hopefully it will all work. I'll let you know after I've got some users to test it.
Many thanks for all your help

Great! It works fine now. Thanks for all your help.