Hello. One of the only things that sends me back to my desktop from my iPad regularly is the inability to archive emails from my iPad Mail.app to DTTG. While I’m sure this is an Apple limitation (what with sandboxing, etc.), is there any way around this at all? Any way to “print” to DTTG (if not save the mail in .eml format)? Lastly, is a proper import function on the horizon? Many thanks.
I do have exactly the same question. Especially as it obviously is possible to access email. HotDoc is able to do it, why Not DTTG?
Unfortunately no. Mail on iOS is completely sealed and unless Apple adds something like “Open In” from Mail there is no way DEVONthink To Go could access your email (except for being a complete email client of its own that accesses your email account).
For posterity and for whomever may (still) be interested: this is now possible by using an alternative email client, named altamail. It allows you to open an email in any other app, such as Devonthink, and seems to store it in .eml format.
If you have an iPhone 6s or 6s+ you can create a PDF in Mail on iOS with this trick: http://m.imore.com/how-print-mail-messages-pdf-3d-touch-iphone
The PDF can then be shared to DTTG.
Some users say that AltaMail is an iOS email app that can share messages.
There are several iOS that can send messages into another app, Dispatch and Airmail are the ones I’ve used in the last 30 days.
And I’d use one of them full time instead of sticking with Mail.app if even one of them handled S/MIME at all arrrgh 
This doesn’t work when I’m out of the house, but I setup a queue in Printopia to advertise an AirPlay printer named “Print to DEVONthink” that lets me “print” an email message in Mail.app and have it converted to a PDF that is moved into my DEVONthink Inbox.
Ahhh… the joys of iOS 
My gripes about iOS are entirely ones that developers could solve if they wanted to (support S/MIME), the only exception is that there isn’t a share sheet for Email but I’m sure there is a radar for it going back for quite a while. No idea why Apple Engineering is avoiding it.