Question

I am trying to create a mail merge to email which also adds an attachment. I am following a procedure outlined in the article
http://word.mvps.org/FAQs/MailMerge/MergeWithAttachments.html

The emails are created and sent to the correct email addresses but the attachments are not being added. I have tested it and the correct file name is being used.

Sub emailmergewithattachments()
Dim Source As Document, Maillist As Document, TempDoc As Document
Dim Datarange As Range
Dim i As Long, j As Long
Dim bStarted As Boolean
Dim oOutlookApp As Outlook.Application
Dim oItem As Outlook.MailItem
Dim mysubject As String, message As String, title As String
Set Source = ActiveDocument
' Check if Outlook is running.  If it is not, start Outlook
On Error Resume Next
Set oOutlookApp = GetObject(, "Outlook.Application")
If Err <> 0 Then
    Set oOutlookApp = CreateObject("Outlook.Application")
    bStarted = True
End If
' Open the catalog mailmerge document
With Dialogs(wdDialogFileOpen)
    .Show
End With
Set Maillist = ActiveDocument
' Show an input box asking the user for the subject to be inserted into the email messages
message = "Enter the subject to be used for each email message."    ' Set prompt.
title = " Email Subject Input"    ' Set title.
' Display message, title
mysubject = InputBox(message, title)
' Iterate through the Sections of the Source document and the rows of the catalog mailmerge document,
' extracting the information to be included in each email.
For j = 1 To Source.Sections.Count - 1
    Set oItem = oOutlookApp.CreateItem(olMailItem)
    With oItem
        .Subject = mysubject
        .Body = Source.Sections(j).Range.Text
        Set Datarange = Maillist.Tables(1).Cell(j, 1).Range
        Datarange.End = Datarange.End - 1
        .To = Datarange
        For i = 2 To Maillist.Tables(1).Columns.Count
            Set Datarange = Maillist.Tables(1).Cell(j, i).Range
            Datarange.End = Datarange.End - 1
            .Attachments.Add Trim(Datarange.Text), olByValue, 1
        Next i
        .Send
    End With
    Set oItem = Nothing
Next j
Maillist.Close wdDoNotSaveChanges
'  Close Outlook if it was started by this macro.
If bStarted Then
    oOutlookApp.Quit
End If
MsgBox Source.Sections.Count - 1 & " messages have been sent."
'Clean up
Set oOutlookApp = Nothing
End Sub

Answer 1

Most likely I am guessing this is your problem

.Attachments.Add Trim(Datarange.Text), olByValue, 1

is Datarange.Text equal to the full path to a file and does that file exist?