Email Marketing: Before starting a new campaign we need to make sure our email passes SPAM Filter tests

We need to cover all major spam filters at ISPs and webmail providers, as well as corporate filters.

Server-side filters

Barracuda
MessageLabs
Postini
SpamAssassin

Sender verification

DKIM
DomainKeys
Sender ID
SPF

ISP filters

Fastmail
Gmail
GMX
Hushmail
Lycos
Mail.com
Mobile Me
Yahoo! Mail

Email Marketing: How to avoid being blacklisted

• Don't use an ISP that has a bad reputation when it comes to spam. Doing so may get you blacklisted just because your IP address is part of their allotted subnet.
• Make sure your DNS is properly set up and that you are complying with the RFC rules regarding service configuration.
• Make sure your Reverse DNS configured properly.
• Configure your sender ID records and SPF properly.
• Make sure your mail server is not an open relay.
• Make sure your proxy server is not an open proxy.
• Check that the abuse@yourdomain.tld and postmaster@yourdomain.tld addresses exist and they are functional.
• Do not allow unsolicited ads and other bulk e-mails to be sent from your server, by the hosted accounts.
• Do not run pro spam services like: spam websites, drop mail boxes for replies to spam e-mail ads, DNS for junk mailers, payment processing services for the products advertised in spam messages, junk mail tools (like lists of e-mail addresses).
• Make sure all your hosts are as secure as possible.
• Make sure you do not have any spam bots on your systems.
• Make sure the information provided in the domain registration service (whois) is updated and complete.
• Make sure your mail server does not send poorly-formatted messages.
• Use secured connections (SSL/TLS) as much as possible.
• Do not allow unauthenticated users to send e-mails neither locally nor remotely.

When you feel that your server is correctly configured and spam-safe, you can use one of the open relay testing and DNS testing tools available on the Internet to make sure everything is working as it should.

If any errors are then reported, they should be fixed before taking any server into production.
Also, never forget that there are distributed lists that do not provide any method of removal from the database. In such cases it is best to prevent being added in the first place.

Email Marketing: Rules for Email Subscribe/Unsubscribe Options

1. A link or Reply-To unsubscribe process must exist in every email sent and these unsubscribe processes must remain functional for at least 60 days following an email campaign.
2. The Reply-To send-an-email opt-out request must remove the address within 10 days.
3. If choosing a link to unsubscribe, the link must either immediately unsubscribe the user on click or, alternatively, lead only to a single page that contains a simple one-page one-click unsubscribe form.
4. The unsubscribe form must consist of a simplified one-step form.
5. The form is forbidden from using persuasive language to entice the person to remain subscribed
6. The form must not contain any advertising.
7. The unsubscribe process cannot lead to additional forms, pages or links or utilize any additional processes to unsubscribe.
8. It must not cost money to unsubscribe.
9. The unsubscribe process may not be hidden behind any login and/or password process.
10. Should Not # Clicking a link in an email that leads to a form that asks the recipient to verify their address, then emails instructions on how to ‘change’ or ‘update’ your subscription.
11. Should Not # Asking for a login or password before proceeding to remove the user.
12. Should Not # Advertising for your products or services on the unsubscribe form.
13. Should Not # Using any kind of multiple step or multiple page process to complete the unsubscription.
14. A visible and operable unsubscribe mechanism is present in all emails.
15. Consumer opt-out requests are honored within 10 days.
16. Opt-out lists also known as Suppression lists are only used for compliance purposes.
17. Accurate from lines (including "friendly froms")
18. Relevant subject lines (relative to offer in body content and not deceptive)
19. A legitimate physical address of the publisher and/or advertiser is present.
20. A label is present if the content is adult.
21. A message cannot be sent through an open relay
22. A message cannot be sent to a harvested email address
23. A message cannot contain a false header
24. Content is exempt if it consists of religious messages, political messages, content that broadly complies with the marketing mechanisms specified in the law, national security messages.

A Suppression List is a list of suppressed e-mail addresses used by e-mail senders to comply with the CAN-SPAM Act of 2003. CAN-SPAM requires that senders of commercial emails provide a functioning opt-out mechanism by which email recipients can unsubscribe their email address from future email messages. The unsubscribed email addresses are placed into a "suppression list" which is used to "suppress" future email messages to that email address.

An open mail relay is an SMTP server configured in such a way that it allows anyone on the Internet to send e-mail through it, not just mail destined to or originating from known users.This used to be the default configuration in many mail servers; indeed, it was the way the Internet was initially set up, but open mail relays have become unpopular due to their exploitation by spammers and worms. Many relays were closed, or were placed on blacklists by other servers.

Email harvesting is the process of obtaining lists of email addresses using various methods for use in bulk email or other purposes usually grouped as spam.