Can DRM take any .txt file (i.e., report writer report, or any other file) and covert it to PDF and email it?
DRM does not convert existing files. DRM will generate a report and export that report to PDF and then attach that PDF to an email.
DRM has no way for you to tell it that you have an existing file somewhere and that you want DRM to go get it and convert it to a PDF. In fact, there is no conversion happening at all. When you generate a SQL or Crystal report dynamically, the SQL and Crystal report engines allow you to export the report you just generated, to PDF. Neither of the two report engines have any ability to take a .txt file, or any file, and convert it to a PDF.