Word to the Wise: Email Best Practices

If you send bulk email, the practices below are the ones that decide whether your mail consistently reaches the inbox, and the worst practices are the ones that most often keep it out. They come from the Word to the Wise (WttW) white paper Email Best Practices (Laura Atkins, 2012), which deals with best practices for delivery, as opposed to best practices for communication strategy.

WttW notes that the paper was first published in 2012 and that filtering has changed since then. Many of its recommendations still apply, and current information is on the Word to the Wise blog (see Deliverability Community Resources).

The Golden Rule

Send mail that recipients want and expect.

In practice, this means that all bulk email should be opt-in. You can still acquire customers by email, but it is more complicated than buying a list of addresses and mailing it. Foundations of Email Deliverability and Two Worlds of Email Deliverability develop the same principle.

A key point: spammers invested heavily in getting mail delivered despite poor reputations, so ISPs and filtering companies built filters that look at the whole of a sender's practice. Bad practices in one stream can affect all of a sender's mail, even when the sender tries to keep good mail separate from bad.

General best practices

Only send opt-in mail

Opt-in means that the recipient gives an email address to the sender so that they can receive marketing mail from that sender. Common gray areas, which are not opt-in when the sender decides for the recipient:

• Giving an email address during a purchase (is that consent to marketing?)
• Giving an address to one division of a company (is that consent for the other divisions?)

This does not prohibit sending updates to customers or cross-marketing, but the sender must think about how to make sure the customer is expecting the mail.

Comply with all local laws

In the United States, CAN-SPAM requires all email to meet these criteria:

Important details:

• CAN-SPAM does not require permission. US law does not make permission a requirement.
• Other jurisdictions require permission to send marketing or commercial email, including the EU (GDPR) and Canada (CASL). Sending without permission there can create legal liability.
• In some jurisdictions, permission cannot be shared or sold, so even buying "opt-in" lists is illegal.
• Splitting purchased lists by country to get around opt-in laws assumes that the seller compiled the data correctly, which is a bad assumption. What actually protects the sender from breaking opt-in laws by accident is getting the recipient's permission before sending.

Practice good data hygiene

• Research indicates that about 30% of email addresses are abandoned by their users every year.
• Abandoned addresses are dead weight: they drag down statistics and make it harder to measure how well the program works.
• Senders should regularly remove addresses that do not respond from their lists. The exact rules for removal depend on the sender, the products and the sales cycle.

Worst practices

Sending mail without explicit permission

This is the most widespread bad practice. A common case: companies add the addresses of buyers to marketing lists automatically, without asking. This is a very common source of delivery problems, especially for one-time purchases. For example, a buyer who bought a gift for someone else has no interest in future mail. They may report the sender as a spammer at a major ISP and never buy from the vendor again.

Buying lists

• Thousands of vendors sell "100% permission based opt-in lists", and many of these lists are nothing of the sort: they are harvested, compiled or stolen.
• Because purchased lists have a history of causing delivery problems and blocklistings, many ESPs prohibit purchased lists outright.
• Purchased lists often contain spam traps and large numbers of addresses that cannot receive mail, which lowers the sender's reputation.
• They are also poor tools for acquiring customers. The lists are resold again and again, the recipients are flooded with mail they did not ask for and ignore offers, and delivery problems can spread to the entire email program, not just the acquisition stream.

Changing domains and from: addresses

Recognition of the sender drives engagement and delivery, at two levels:

• ISPs recognize senders by the combination of IP address and sending domains.
• Individual users recognize email by what appears in their inbox (the from address).

Plan any changes to domains, IP addresses and from addresses, to reduce the risk to delivery. (See IP Warm-Up Recommendations for changes of IP address.)

Affiliate programs

• Careless affiliates can cause major delivery problems even for a sender's opt-in mail. Some affiliates hire sub-affiliates who spam on the brand's behalf without its knowledge.
• Financial incentives attract unscrupulous mailers. Too much spam advertising a particular product or service can damage the reputation of all mail for that product or service, including legitimate opt-in mail, receipts and transactional mail.

Conclusion: reputation tracks across streams

• The best way to reach the inbox is to send mail that recipients want and expect, and to ask for permission first.
• Make clear what recipients are signing up for, and keep those promises. Do not send daily email to someone who signed up for a monthly newsletter, and do not share lists with other vendors without explicit permission.
• Reputation can follow a sender across several mail streams. Poor practices in acquisition marketing can affect retention and transactional email. Even when senders think their reputation cannot be tracked and applied across streams, it often is. (This is the argument for keeping streams separate, as described in Advanced IP Segmentation, but remember that separation does not make bad practice acceptable.)