Upon merging using the merge wizard, it merges to emails and writes a custom subject field based upon the merge fields. The problem isn't with the VBA code though, if I disable the VBA code, it still has the same problem behaviour, that of when connecting to a previously used file, if the contents of that file has changed, it doesn't seem to read all the rows, only the number of rows upto the maximum of the previous merge, i.e if the last merge had 5 lines, it will only read the first 5 lines even though the excel data source now contains 10 lines.

My users can work around this by saving to a new filename and choosing that as a new data source, but I don't understand why this behaviour is happening.