This is a plea…
I have DT Pro 2. I’d love to add email archiving, but really don’t need all the other advanced features of DT Pro Office. So it’s hard to justify the $70 upgrade cost.
To me, email archiving is something a lot of users might want. Storing decades worth of old mail in your email client is asking for trouble. So I suspect I’m not alone here.
I’d like to ask you to consider a half-way house - a way of adding email archive to DT Pro for somewhat less cash 
On a related note, does the email archive function work in other email clients such as Postbox?
I did download the demo to try this out for myself but the email archive function doesn’t seem to work without a full licence.
If I knew what I know now after using DTPO and DTTG in about one year I would easily pay $1.000 for the app (Hope that the developer does not see this post.)
It has helped me more than any other app, its a complete system not just an email archiver.
I have wondered many times how the intelligent search system works, but I don´t have to worry it just works. I tested Evernote for a short time before I knew about DT but these apps are lightyears apart. And I am still an amateur, not by any means a pro.