Android Question How to get and attach multiple files to email using phone library

I have tried to search but cannot find something that exactly answers my question, at least not with a code example.

My problem is that i can't seem to add multiple files using attachments.add
and further more not create a list of files to add.

In short, i want my app to search for all files containing a certain prefix in afolder and then add all of them as attachments in a mail.

Best regards.

EDIT: Found answers, thread can be removed