CRM 2011 - Custom OnDemand workflow on selected records of a view

Hello everyone,

I have a question regarding custom OnDemand Workflows. There is a business requirement, that the user selects one or more records in an entity view and starts a process to send some automated E-Mails based on the information of these records. 

My question is:

Is it possible that I create a custom OnDemand workflow, which executes on the selected records of a view (via the native Workflow Ribbon Button of the View), but run the Workflow only once? I need some grouping logic on the selected records so there will be no E-Mail per record but the amount of E-Mails will be less then the selected records...

So technically I need following possibility:

User selects many records of a view

He triggers himself the workflow through the ribbon button on the view

I get all the selected guids in my workflow and run my logic, send my E-Mails

But, the workflow which the user runs is only executed once and not once per selected record

Thanks for any help on that

Regards

John