Looking for DDG's e-mail service, I suggest a partnership with Lavabit.com. How about "LavaDuck"?

Lavabit's good for non-paying users, and better for the paying ones (I'm one of them).

Among lots of good things, I selected the following points to you -- please don't read only it, follow the links and be happy :D

In their Terms of Use:
"[...] Advertisement
In their Privacy Policy:
"Lavabit will not release any information related to an individual user unless legally compelled to do so.
[...]
For premium users who have elected to use our “secure” service, incoming e-mail is stored using an asymmetric encryption process that guarantees that it can’t be accessed by anyone except the holder of the account password. For these accounts, only the encrypted version of the message is ever saved to disk. [...]"

Which leads us to their security concerns:
"[...] In safer times, a strict Privacy Policy would have been enough to protect the rights of honest Internet citizens. But everything changed when the United States Congress passed the Providing Appropriate Tools Required to Intercept and Obstruct Terrorism (PATRIOT) Act in 2001. If you’re currently unaware of the PATRIOT Act, we highly recommend you visit the Electronic Frontier Foundation (EFF) website. [...]
Lavabit believes that a civil society depends on the open, free and private flow of ideas. The type of monitoring promoted by the PATRIOT Act restricts that flow of ideas because it intimidates those afraid of retaliation. To counteract this chilling effect, Lavabit developed its secure e-mail platform. We feel e-mail has evolved into a critical channel for the communication of ideas in a healthy democracy. It’s precisely because of e-mail’s importance that we strive so hard to protect private e-mails from eavesdropping. [...]"