It can't actually know that the report printed or exported... it only
knows that the attempt was made.  If you are using a command button to
export the report, then add a line after the line that generates the
report, that updates the table.
Here is an example:

dim db as dao.database
dim sSQL_WHERE as string
set db = currentdb( )
sSQL_WHERE = " [FieldOne]=" & num1 & " [FieldTwo]=TRUE"
db.execute "UPDATE tblSomeTable SET [Printed] = TRUE WHERE " &
sSQL_WHERE

sSQL_WHERE must be set to the WHERE portion of the same query that the
report is based on with the same parameters.

Create a procedure that performs the export, then add an update query that
changes the records from "To Send" to "Sent".

''''Sample - AirCode
Public Sub ExportReport()
  DoCmd.OutputTo acOutputReport, "MyReport", acFormatSNP,
"C:\MyReport.snp", 0
  DoCmd.RunSQL "UPDATE MyTable SET [Status]='Sent' WHERE [Status]='To
Send'"
End Sub

Fred Zuckerman

There is no way for Access "know" if the export worked or the report was
printed.
When I need to confirm this type of activity, I add 2 fields to the detail
table.

ExportID      Long integer
ExportC       Yes / No

Before doing the report or export, I write one export ID number into all the
records selected.
Once the export or report is completed the user will use the export ID to
set ExportC to true.