Issue
I have searched from here to the ends of the earth and have still not figured out how this is possible.
I started with using the custom built javamail/gmail api because I wanted to send the email in the background without any interaction from the user.
I then tried to build ontop of that: crypto ( http://javamail-crypto.sourceforge.net/ ) coupled with bouncycastle ( https://www.bouncycastle.org/ ) to sign the email
Because these api's are so old, they clash a lot and every time I seem to fix one obscure error, I uncover another.
I have seen 1 or 2 apps on the market that provide S/MIME encryption and have emailed the creators but have not received a reply.
Solution
I've officially given up, its not a case of how old the API's are but a combination of the following two problems:
There is no java.awt package in Android, but a custom andrioid.awt one. I have tried editing the jar files belonging to bouncycastle to adapt to this but to no avail.
The api's seem to not correspond with each other at all. Every time I got close to signing the email and sending it, I would find a nosuchfieldexception or nosuchmethodexception at runtime where one api was looking for something in another api.
Eventually, I just gave up trying to do it for free and found a site called Chilkat who have a perfectly working API with a 30 day trial from the first time you run the code.
Their android api's are here: Chilkat for Android
The reason I'm putting this up is for anyone else who's gone through as much blood and sweat over this as I have to know that there is some hope, even if you have to pay for it...
Answered By - Kitteh
Answer Checked By - Clifford M. (JavaFixing Volunteer)
