Hummm.. This thread is just what I got by searching the Net for a developers' guide to creating emails - no answer. I was about to ask the same thing but decided to attach to yours.
I'm seeking a list of how to compose emails where I can send nicely formatted HTML/CSS for an upcoming newsletter as well as order confirmations - and a low spam score.
There are only a few things that affect spam if you think about what an email consists of that a computer can quantify: the sending domain/IP properties and the email content (header, images, links, text). Here is what I've done to improve the spam ratings of our outgoing emails. However, some emails still get a spam score too close to flagging it as spam. Some servers will put our valid emails in the recipients' spam folders.
1. Enable SPF.
I have SPF enabled with a tight filter (reverse-DNS). SPF will specify which machines are authorized to send email from my domain(s). This means that only mail sent through this server will appear as valid mail from your domain(s) when the SPF records are checked.
Get white-listed on some major email servers such as AOL, Comcast, Yahoo mail. You can do that _only after being grey- black-listed which is too late for customers who didn't get valid emails. Of course, postmasters don't tell you when you're grey- black-listed.
3. Hyperlink format.
Avoid using hyperlinks where the display text is not the link itself. This one baffles me because I receive emails with hyperlinks whose display text is different than the link itself. But, I read somewhere to avoid that.
Use escaped sequences (e.g., in a query string, use "&" instead of just "&") (http://en.wikipedia.org/wiki/Interne...cal_censorship).
4. Subject Line.
Plain Characters, Alphanumeric, in the Subject.
Avoid special characters in the subject.
No extraneous images. Keep image size small. (These are my ideas based on common sense.).
Use correct spelling and grammar. Do not use words made up of both letters and numbers, such as v1agra or ref1nance.
Avoid spam-catching copy such as "click here", offensive words, adult content.
Use a high ratio of friendly words to words commonly found in spam (http://en.wikipedia.org/wiki/Bayesia...tering#Process).
7. Clean IP.
Our email server was moved to one that a bad user had in the past. When that happened, some of our emails weren't getting through and I saw our spam setting increase to more spammy. I had our host change us to a clean IP that solved the problem.
8. HTML Formatting.
Use correct syntax.
Escape non-alphanumeric characters such as "&".
THINGS BEYOND MY CONTROL
1. Recipient Knowledge.
The recipient can click the "spam" link not knowing exactly what that button meant. I've had customers think it was a "delete" button. Then, their host sees a lot of this and marks your sending credentials as spam.
2. The format/encoding of the recipient application.
This affects more the appearance than the spam setting. E.g., what if they convert the HTML to text format? I guess using multi-part encoding is the solution.