this is a long standing issue....
the problem is realname and email are formmail special fields.
for various reasons formmail doesnt fill special fields.
the workaround is to rename the fields to, say, Name and Email, and then derive the special fields from these new ones:
check the how to doco for more details on derive_fieldsHTML Code:<input type="hidden" name="derive_fields" value="realname=Name,email=Email" />