Having resolved the connection string problem, we're now trying to use the SendEmailWithAttachment plugin to send the derived spreadsheet to the client as an attachment. The emailing is done in an archive operation on the source file before it's moved to an archive folder.
The archive op works but no email is generated and no errors are logged anywhere.
Is there a setting we can change or something we can put in the plugin xml to log useful information? Setting Debug = 1 in Jitterbit.conf's Operation Engine section hasn't shown up anything more.