What Is an Email Blacklist?
by Emma Contreras
With email phishing attacks on the rise year after year, email blacklists are necessary tools that help maintain inbox safety and security. Blacklisting is the process of identifying IP addresses associated with sending malicious email messages, such as spam, and then blocking those emails from being delivered.
An email blacklist is a database that identifies which emails are spam. Being on a blacklist can greatly affect deliverability rates.
Email blacklists help people avoid receiving a high volume of spam. However, they can also be obstacles for organizations that are attempting to send legitimate messages to their subscribers.
If your healthcare organization wants to run successful email marketing campaigns and send out HIPAA compliant email, you need to understand how email blacklists work, how to know if you’ve been blacklisted, and how to avoid them.
SEE ALSO: Healthcare Email Marketing Use Cases
How do emails get blacklisted?
Even if you end up on an email blacklist, that doesn’t necessarily mean you’re sending out harmful email. There are a number of reasons you could have been blacklisted, including:
- Failure to maintain proper email list hygiene: If you don’t regularly monitor and clean up your email list, you may be unknowingly sending messages to inactive addresses, addresses with typos, or spam traps. Attempts to email these types of accounts harm your sender reputation.
- Failure to remove unsubscribers: Continuing to send messages to addresses that requested removal from an email list could get you blacklisted.
- Sending a high volume of email: Nearly 80% of email sent on a daily basis is spam. If your IP address is showing a higher email delivery volume than other IP addresses, a blacklist may flag you as spam. Or, if you suddenly increase the volume and frequency of your messages, you could be flagged as spam and blacklisted as well.
- User-submitted spam complaints: It’s common for an organization to receive some level of complaints regarding its email marketing. However, if too many recipients flag your email as spam, you may be blacklisted.
- Putting red flags in your content: ISPs can now filter emails by certain keywords or images. Using too many exclamation marks, all caps, and certain phrases such as, “Money-back guarantee” or “Claim your prize now!” can result in being blacklisted.
- Hackers sending spam: It’s possible that a hacker has accessed your account to send email spam or could be using your IP address to send spam.
Types of email blacklists
There are three kinds of email blacklists your organization should be aware of:
Public blacklists: These blacklists are available to the public to check. Public blacklists don’t actually block your email messages from being delivered; rather, different inbox providers can pick and choose which public blacklists they want to use as part of their filtering process.
Private blacklists: Internet service providers (ISPs) and email providers can use their own internal blacklists to monitor and filter out spam email. For example, Gmail has its own private blacklist that filters out spam.
Enterprise spam firewalls: Organizations and companies can utilize anti-spam software that will help filter out spam email and blacklist certain IP addresses from sending future messages.
How to avoid ending up on an email blacklist
Your organization should take proactive steps to avoid being placed on blacklists. If you don’t, your future deliverability will be affected.
- Regularly monitor and clean up your email lists. Remove unresponsive subscribers, honor unsubscribe requests, remove addresses with typos, and use email validation tools to check the legitimacy of the addresses.
- Use double opt-in verification for new subscribers: One way you can ensure your subscribers are real people and to ensure they actually want to receive your messages is to use a double opt-in method.
- Comply with the CAN-SPAM Act: A violation of the CAN-SPAM Act can cost you thousands of dollars. Avoid costly fines and potentially being blacklisted by providing an unsubscribe option in each message, honor opt-out requests promptly, and clearly state if a message is an ad.
- Use security software to avoid email hijacking: With the help of IP checking tools and malware protection, you can avoid becoming the target of an email hacker. You can also check IP email blacklists to see if your IP address is being used by another server, which is a strong indicator that you’ve been hacked.
Email blacklists can affect your ability to communicate with patients
While it’s not always completely possible to avoid being blacklisted, know that these are not permanent placements. Following proper email etiquette and maintaining your email lists will go a long way in keeping your messages out of people’s spam folders and boosting deliverability rates.