Dos and Don’ts to avoid email blacklisting, and the junk folder

Companies and other organisations (such as universities and governments) providing email to their staff, as well as mail hosting providers (such as Gmail and Hotmail) providing email to the public, put various measures in place to try to make sure their users get the emails they want, and block the emails they don't want.

The easiest way to get to a user's inbox consistently and avoid email blacklisting is to keep sending them only e-mail that they want.

As mentioned in our beginners’ guide to email blacklisting, an email spam filter maintains internal and external sources of blacklists, and any mail that are on this list would be prevented from reaching its intended destination. To ensure that your emails are being delivered to the intended recipients, the sender’s reputation, credentials and content will need to be accepted by the spam filters first before this can transpire.

How do spam filters know when a sender is good?

Reputation metrics. To determine a sender’s reputation, it has to be earned. A sender needs to build up a history of good and consistent email sends, that bring with it a history of subscriber engagement metrics – how the recipients reacted to this mail:

Positive reactions:

  • Open the emails.
  • Reply to the emails.
  • Flag or mark emails as important.
  • Forward the email.
  • Click on links in the email.
  • Keep the email and not delete it.
  • Whitelist the sender.

Negative reactions:

  • Mark the email as spam.
  • Send in an abuse complaint.
  • Create a filter to delete similar emails.
  • Blacklist the sender.
  • Not even open the email (negative engagement).

To manage your email reputation, these do’s and don’ts will ensure that  you keep sending email that people want to receive, have positive subscriber reactions to your mail, and ensure that no spam filters view your mail as junk, successively escaping the dreaded blacklists.

The DOs:

  1. Always get permission to send email to the recipient. Following email best practice and using the double opt-in method will reduce complaints, bounce rate and spam labelling, and improve inbox delivery.
  2. Always include an unsubscribe link that is clearly visible to the reader to avoid spam labelling. Also ensure that this link is active for at least 30 days after sending.
  3. Include credible ‘from’ and ‘reply-to’ addresses and avoid the ‘[email protected]’ email addresses. Emails with ‘from’ addresses that have jumbled letters and numbers in them, like [email protected] or [email protected] will more than likely be reported as spam.
  4. Be recognisable. Add your logo to the email header and customise email templates to match your website or brand’s colours and style.
  5. Supply your physical address and contact details within your email message, or at least a link to your contact page on your site.
  6. Size matters, so do keep your message size below 30KB by excluding unnecessary text and images.
  7. Employ the email best practice of whitelisting, which is to ask your subscribers to add your email address to their contact list.
  8. Include a ‘view online’ button in your newsletter. Your HTML email template often doesn’t display like you want it to on every mail client. So, offering your subscribers the option to view a web-based version of your email will ensure better visibility of your email. That being said, always use inline styling for certain clients to read your CSS.
  9. Always include a text version of your HTML email. Not only will this help for subscribers that cannot read HTML, but this improves your spam score as well.
  10. Before hitting send, always test your email meticulously for broken links, typos or other HTML breaks that might have occurred when content was added.
  11. After sending, monitor the statistics for each campaign to identify what is working and what content is not resonating with your subscriber base. Compare data in respect of delivery, complaints and bounce rates to identify trends that may prevent future delivery problems.
  12. Regularly monitor IP blacklisting services to ensure you are not blacklisted. Your ESP should be able to provide this service for you, and alert you if you do end up on a blacklist, but ask if you’re interested to see the status of your IP anyway and to find out what you can improve to ensure better delivery of your mail.
  13. Also consider your times of send. Simply develop a regular email pattern and stick to it, and just tweak your sends accordingly to your engagement metrics.
  14. Consistently practice good list hygiene. Repeated bounces, misspelled or old email addresses must be removed or you are at higher risk being hit by spam traps and labelled as a spammer.

The DON’Ts:

  1. Avoid spam trigger-words, especially in the subject line. Examples of this are: ‘free’, ‘click here’, ‘money back’, ‘cash’, ‘porn’ and ‘opportunity’.
  2. Don’t use ALL CAPS in the subject line or email body. It is a spam red flag and detrimental to your email reputation – mostly because it is pushy and annoying.
  3. Email body text should not be in loud colours, such as red (#FF0000), green (#00FF00) or blue (#0000FF).
  4. Don’t overuse punctuation marks such as !!!!!, or symbols such as $$$; use descriptive language instead.
  5. Avoid over-emphasising call-to-action buttons with loud colours or CAPITALISATION.
  6. Don’t convert MS-Word files to HTML or use bad HTML coding to compile your message.
  7. ‘Re’ or ‘Fwd’ should not appear in the subject line to trick users into thinking that it is a continuation of an earlier conversation. If you have their permission, you don’t need tricks.
  8. Never have image only email newsletters. Spam filters cannot read the text on images, which causes red flags, regardless of how good your content is. Your content needs to be a balance of the two. Check your Image-to-Text ratio to see whether your text or images are outweighing the other.
  9. Don’t make misleading claims in the subject line. The body copy must deliver what the subject line promised.
  10. Avoid adding attachments to your messages, rather provide a download link. Not only will your message be less likely to be flagged as spam, but you’ll also be able to track who downloads the files you want to provide to your subscribers.
  11. Do not send to the same list multiple times in one day. This is also grounds for blacklisting. Your subscribers have enough mail in their inbox - at most you should be sending daily, depending on the nature of your business.
  12. And finally; do not, I mean DO NOT use purchased lists. Ever. There is no such thing as a clean purchased list.

By sticking to email best practice and integrating all of the tips above into your email marketing campaigns, your reputation score will increase as subscribers react positively to your mail, and thus ensure that no spam filters view your mail as junk. But if you do the opposite, it will simply decrease – and you will notice higher bounce and complaint rates, and eventually land yourself on a blacklist.

The bottom-line:

Being added to an email blacklist seriously hinders inboxing and can be a nightmare to reverse. So, while it may look like more work, you will have a more reliable inbox delivery in the long run. The key is to follow the basic HTML design tips regarding text and layout, and always, I mean always, test before you send. Additionally, by proactively monitoring campaigns, deliverability and regularly cleaning out your subscriber list maintains a great reputation further and will constantly result in good delivery and can furthermore be added to a whitelist.