Whitelisting website email so it is not rejected as spam

Take a look at the service these guys offer

Mail Chimp

In most cases it ends up being better to just integrate with their API. I run a website myself and use their services and they are way better than anything i could write myself.

Even if you don't use mailchimp take a look at the contents of one of their emails and pretty much copy it - then it should go through. I think you need to collect a few details about your user such as their name etc and personalise each email.

Also, think carefully about the amount of emails you will be sending. If it's enough for your ISP to blacklist you then you may end up with no Tinterwebbage.

Hope this helps

Ok, I spend a couple hours this morning researching the answer to this question and here's what I discovered.

DNS Setup

1. Ensure forward and reverse DNS lookup is enabled.
2. Ensure web server has a static IP address.
3. Add a SPF Record

Email signing:

1. Sender ID
2. DomainKeys
3. DKIM

Major whitelists

1. ReturnPath.net
2. Goodmail

Conversations with major vendors

1. Yahoo
2. Google
3. AOL: aol.com, cs.com, netscape.net
4. MSN: Hotmail, Live.com, MSN (uses ReturnPath.net certification)
5. United Online: Netzero, Juno
6. Verizon
7. AT&T: att.net

Other helpful information: Deliverability.com

Here's some good info if you're looking to off-load this to a provider:

https://stackoverflow.com/questions/3746213/sendgrid-vs-postmark

https://stackoverflow.com/questions/4798141/sendgrid-vs-postmark-vs-amazon-ses-and-other-email-smtp-api-providers