Thank you for your feedback! We do have plans to support pretty much any type of attachment, though you would only be able to actually view a small portion of those types in the mSecure app. For example, at first release of v6, you will be able to attach and view image and PDF attachments. In the future, we'll add the ability to attach all sorts of other types of attachments, but in the end, you may only be able to open and view the contents of images, PDFs, .text or maybe .doc and a couple others, if that makes sense. At this time, I don't have all the details on what actual types of attachments will be viewable, but I know that only a few will be supported.
I don't really care about viewing the attachment in the app - just make it easy to attach and the export attachments - the mSecure app doesn't need to worry about the format and providing a viewer.
The way you are talking about the feature is how it will work for most attachments. They won't be able to be viewed, but they will be able to be encrypted and attached to records, and then the can be exported for viewing at a later time.
I see there are a few requests for attachments of any file type. If you could add support for .zip files that would provide any file type support. My current desire is to be able to put Google keystore.jks files.