What ones are missing? What is criteria of the sort for the mail merge? The missing records may have invalid data in the sort field and so are rejected and will not show up as a recipient. I used to do a mail merge getting data from a core system, rejecting duplicated addresses, so they would not show up, then sorting them on zip codes. Note, I did not remove the duplicated addresses from the mail merge, I only allowed the first address. the rest did not show up in it. Next I sorted on valid zip codes, valid zip codes have to be alpha numeric because all they will be stripped of leading zero’s if you use numeric with data entry, also if you have used “O’s” instead of “0′s” in the field this will also causing a rejection of the data.