Importing lists of contacts into SigParser is designed to be very easy.
Go to the Contacts or Companies screen and click Import
Select a file (csv or Excel file)
Map the columns in the file to SigParser fields.
Click upload and wait for the list to finish process.
SigParser will match contacts on email address and companies on domain names and will ensure duplicate contacts and companeis aren't created during the import process. So it is safe to re-import the same list over and over again.
You can view details on previous list uploads by going to the Contacts -> Import page again and at the bottom you'll see all the imported files.