In Publisher, you can loop a field to distribute by email to different users even without reducing data, if that's the case. The only thing you need is to include those email addresses in the script using any valid source (INLINE, excel file, database table...). You only need one task to do that, instead of creating as many tasks as possible recipients.
Set Reduce by Region, using "Reduce By Field Value".
Use the "Reduced Document Name" textbox to configure the name of the report (for example, using the value of the field Region).
Then go to the tab "Distribute" in the same task, select "Loop Field in Document", click on "Open Document" and select your field "Email Address" and set "Check user identity on" "Email Address", and click on "Target Type:" "E-Mail".
Finally, in File Type, click on "PDF Report from Source Document" and select the report ID you want to send by emailfrom your QVW.
Apply to save settings and run the task: it should reload first, then reduce and create as many PDF files as regions and recipients, then send them by email, in the same task.