Hi moepyag,
Refer below article.
Export GridView to PDF and send PDF File as email attachment in ASP.Net
In this line of code, you need to specify the name of the File based on your person name instead of GridViewPDF.pdf.
mm.Attachments.Add(new Attachment(new MemoryStream(bytes), "GridViewPDF.pdf"));
Example:
//Get the name from the GridViewRow.
string personName = "moepyag";
mm.Attachments.Add(new Attachment(new MemoryStream(bytes), string.Format("{0}.pdf"), personName));
For more details on fetching GridView row details refer our article.
Display GridView Selected Row data in TextBox outside GridView in ASP.Net