Hi William,
Thank you for your interest in Syncfusion products.
The document.MailMerge.Execute method updates all the occurrence of the specified merge field in document and clears all other unmatched merge fields from the documents. For merging the fields one at a time you can make use of the overload method - Execute(string[ ] fieldNames, string[ ] fieldValues).
DocIO has a Boolean property document.MailMerge.ClearFields (by default it is set as true) which removes all the unmatched mail merge fields from the document while mail merging. We have to set document.MailMerge.ClearFields property as false, to preserve the unmatched mail merge fields in the document before calling document.MailMerge.Execute method.
We have prepared a sample to illustrate your requirement of mail merging without removing the unmatched mail merge fields in the document. Please do find the sample from the following location.
Sample Link:
Sample902407720.zipFor more information regarding mail merge functionality of DocIO, please refer the following User guideline link:
http://help.syncfusion.com/ug_93/Reporting/DocIO/ASP.NET/Documents/46mailmerge.htmThere is no change in the functionality of Execute() method from 7.3 to current release. Could you please share us your sample application and assemblies used (7.3 version) to reproduce the mentioned issue on our side.
Please let us know if you have any other questions.
Regards,
Poornima