I’m not an ex-atheist, so I can’t speak from that perspective, but my faith has been the foundation I’ve built my life on and the lens through which I see and interpret the world. So you won’t be surprised that my suggestion is: yes, you should explore faith :)
We just released version 4 of Direct Mail. The big new features include cloud syncing/collaboration, autoresponders, and a redesign for OS X Yosemite. Companion app for iOS also available at http://directmailmac.com/stamps.
Calling sandbox_init from inside your app has been deprecated in favor of the App Sandbox mechanism, but I don't see any indication that sandbox-exec is deprecated.
You can execute the process under sandbox-exec to take advantage of OS X kernel-level sandboxing. You'll need to write your own profile file that allows/denys what you want. There are plenty of examples of these .sb profile files under /System/Library. More: https://developer.apple.com/library/mac/documentation/Darwin...
While you're waiting for them to get back to you, maybe I can tempt you to give our email campaign service a look? http://www.directmailmac.com. If you have any questions, we have live chat support available starting 7 AM PT tomorrow morning. Good luck!
If you don't want to sign up for a Litmus subscription, you can use Direct Mail for OS X (http://directmailmac.com) to run design tests on a pay-as-you-go basis. Also inlines your CSS by default (but can be turned off).
Thanks! We have additional integrations planned, but if you have something in particular in mind, please drop me (Jonathan) a note: http://directmailmac.com/support. Thanks for the feedback!
If you click through and submit a meeting, you're rewarded with some clever artwork making fun of the hot websites of the day (Facebook, Foursquare, etc.).
I'm the developer of Direct Mail, if you have any questions. We have several customers using Direct Mail with SendGrid and they seem to be very happy with the setup.
Disclosure: I work there.