If you want to attach an extra file to an outgoing email, then you can use the advanced, utilities workflow component, From file to attachment to achieve that.

(This is a duplicate of the File to attachment component).

The component has these parameters:

1. File path
   This is the path to the file, that is to be attached.
2. Attachment name
   The name of the attached file. So you decide for a name of the attachment independently of the original file name.

If you see an attachment name when you receive the email like this:

Then you are probably using an invalid characters in the attachment name. There is no standard as to which characters, that are allowed so you need to test for invalid characters and e.g. replace characters not found in the lists: a-z, A-Z and 0-9. On one mail server the dash (minus) character caused such an attachment name.