[rglover]

Guessing you've already done it, but I worked on something loosely related to this a couple years back and best things you can do to avoid it are:

1. Make sure you've done DKIM and SPF verification via your SMTP provider.

2. Use an SMTP provider with a solid sender reputation (e.g., Postmark).

3. Help users keep lists clean. Aggressively handle bounces and make sure unsubscribe is easy to avoid spam complaints.

P.S. Dig the design/feel of everything. No immediate use but I've bookmarked to come back and give it a try when I do.