When an email copy contains a URL, its domain will be tested to check if it has been listed on a blocklist by providers such as Spamhaus).
‘Clean’ suggests that there were no URL is the email body that was blocklisted.
<IMG of Report>
A domain blocklist (also known as a DNSBL or RBL, Domain Name System-based Blackhole List) is a list of domains (websites or email sending domains) that are flagged for sending spam, malicious content, or engaging in other undesirable activities such as phishing or fraud. These lists are maintained by various organizations and email security services to help email providers (like Gmail, Outlook, Yahoo) and other online services filter out potentially harmful or unwanted communications.
When a domain is included in a blocklist, emails or other types of communications from that domain may be rejected, filtered into the spam folder, or flagged as suspicious by the receiving mail server.
Why Domains Get Blocklisted:
Sending Spam: If a domain sends a high volume of unsolicited or unwanted emails, it can be flagged as a source of spam.
Malware or Phishing: If the domain is associated with malicious activities such as distributing malware or conducting phishing attacks.
High Bounce Rates: Continuously sending emails to invalid or non-existent email addresses can get a domain flagged, as this behavior is often associated with spammers.
Spam Complaints: If a significant number of recipients mark emails from the domain as spam, email providers might add the domain to a blocklist.
Using a Shared IP: If the domain shares an IP address with other domains that send spam, it could be blocklisted even if it's not the direct source of spam.
Spam Traps: Sending emails to spam traps (inactive or fake email addresses designed to catch spammers) can lead to a domain being blocklisted.
How Blocklists Work:
When a domain is blocklisted, email servers and other online services can consult the blocklist to determine whether to accept, reject, or filter communications from that domain. These blocklists are updated regularly based on reports of spam or other malicious activities.
Common Domain Blocklists:
There are several widely used domain blocklists maintained by different organizations. Some of the most common include:
Spamhaus: One of the most widely used blocklists that tracks domains involved in spam or malicious activity.
SURBL (Spam URI Realtime Blocklists): Focuses on identifying and blocking domains linked in spam emails.
URIBL (Uniform Resource Identifier Blacklist): Blocklists domains found in the body of spam emails.
Barracuda: Tracks domains known for spamming or engaging in malicious behavior.
SpamCop: Uses reports from users and systems to block domains involved in spam.
Consequences of Being Blocklisted:
Emails Marked as Spam: Emails sent from the domain are likely to end up in recipients' spam folders or be rejected outright.
Reputation Damage: Being blocklisted harms the domain’s reputation, making it harder to deliver legitimate emails even after resolving the issue.
Reduced Deliverability: Other domains or ISPs may refuse to accept emails from blocklisted domains, leading to a drastic reduction in email reach.
How to Check if a Domain is Blocklisted:
You can use online tools to check if your domain is listed on any blocklists. Some popular tools include:
MXToolbox: Checks your domain across multiple blocklists.
Spamhaus Blocklist Removal Center: Helps you identify if your domain or IP is on their blocklist.
Barracuda Reputation Lookup: Provides information on whether your domain is blocked by the Barracuda network.
How to Remove a Domain from a Blocklist:
Identify the Reason for Blocklisting: Investigate why your domain was flagged. This could be due to sending spam, using compromised email accounts, or associating with other malicious activity.
Fix the Issue: If your domain was flagged for sending spam or phishing emails, clean your email list, stop sending spam, or secure your accounts.
Submit a De-listing Request: Most blocklists provide a way to request removal. You’ll often need to provide evidence that the issue has been resolved (e.g., SPF/DKIM setup, fixed security breaches).
Monitor for Recurrences: After being removed, continue to monitor your email sending practices to prevent being re-listed.
Best Practices to Avoid Being Blocklisted:
Maintain List Hygiene: Regularly clean your email lists to remove invalid addresses and disengaged users.
Use Email Authentication: Implement SPF, DKIM, and DMARC to improve email deliverability and ensure your domain’s reputation is protected.
Monitor Spam Complaints: Use feedback loops to monitor and address complaints from recipients who mark your emails as spam.
Avoid Sending to Spam Traps: Validate your email list using email verification services to avoid sending to spam traps.
Warm-up New Domains: Gradually increase sending volumes for new domains to build a good reputation over time.
By following these steps and keeping an eye on blocklists, you can help prevent your domain from being flagged and improve overall email deliverability.