Design logo and icon for DevInbox, dummy emails for developers.

This is what DevInbox (casing/color can be changed) was looking for in their logo design

DevInbox is a new Saas that allows developers to create dummy emails for testing applications. It competes with MailTrap, Mailsac, Mailinator, or Mailsaour.
The logo/icon will be used in https://devinbox.io (we showwhat like about the current icon+logo, but it's too generic).
We like the black and white, but maybe an accent color could be useful to make the icon remarkable, or also a different graphic of the letter?
The logo will be composed of the icon (also alone as favicon) + DevInbox.
SVG for the icon is preferred. Read more