Hi John - The short answer is no :( You can't import a list to build a match query. But this is the workaround I use all the time.
1 - Create a view with just the minimum fields (e-mail, do not allow bulk E-mails, etc.)
2 - Export the view (be sure to select make this export available to re-import)
3 - Open the Exported XML and your CSV file in Excel
4 - Do a vlookup Excel formula on the E-mail to see which of your Active Contacts are in the CSV list and update the
5 - Update the Do Not Allow Bulk E-mail field in your Export from the results in #4
6 - Re-import the Exported XML file
Note: Be sure to temporarily suspend any De-Dupe rules you might have running while you do the re-import
If some of these terms (XML, vlookup, De-Dupe rules, etc.) be sure to poke around on YouTube and other internet searches. The update process is quite sensitive, you'll likely inadvertently create several duplicate imports before you get it right with
an update. You can easily delete the imported records in bulk by looking at the Data Management section.
Good Luck.
Tom