One of the long time requests for Tableau Server is for the ability to schedule e-mails that contain a PDF attachment rather than just a PNG. Along with that requirement usually comes two others: first, the ability to export all of the sheets in a scrolling worksheet within a dashboard and secondly, to add some kind of watermarking / logo / timestamping to the export. A lot of different solutions have been put out there, since technically tabcmd has most of these abilities, but the actual implementation has been left to the end user.
I've put together a tool called Behold! Emailer which is a Windows program that ties all of the necessary pieces together to get as close to these requirements as possible within the current Tableau Server framework. It uses the techniques from the VizAlerts project to allow end users to choose their schedules right through the standard Tableau Server UI, but it handles all the of e-mail generation through tabcmd. It's not intended for bursting out e-mails to users who are not in Tableau Server, but to supplement the existing subscription capabilities. If you have these needs, please take a look at: