What is the SORBS Spam Blacklist ? Definition
SORBS (Spam and Open Relay Blocking System) is a blacklist designed to block emails from IP addresses suspected of sending spam, phishing, or malware. Being listed on SORBS Spam doesn't always mean landing in spam, but can impact email transmission from the specified IP address, including dynamically allocated IP addresses.
But it can also have zero impact. We'll cover that below.
SORBS blacklists IP addresses, domains, or email servers when it detects that they are attempting to transmit or relay spam. IP addresses may be included in the DNS-based block list as a result of repeated instances of sending or forwarding spam or other malicious email messages.
With more than one million host servers identified as sources that disseminate spam, the SORBS Spam database is well-known in the industry.
That's the theory. Now, we'll cover the factual stuff.
How do I know if I am listed on Sorbs Spam Blacklist ?
[MUST READ for Gmail & Outlook users]
The biggest email providers which are Gmail (including Google Workspace) and Outlook (including Office365) have a significant number of their sending IP addresses listed in SORBS Spam.
And still, Gmail and Outlook are in the Top 2 email providers to land in the inbox of your recipients. Keep reading. Teaser: both don't care of external blacklists like SORBS Spam to decide where your emails land.
Gmail and Outlook both use large pools of IP addresses to send out the emails of their users.
When you send an email from Gmail or Outlook, the service selects one of these IPs to use. The next time you send an email, even if it's just a few minutes later, it's possible that a different IP address could be used.
This explains it all.
In other words, if you send emails using Gmail or Outlook and you found out that your sending IP has been listed on SORBS Spam, that's pretty common and that's NOT because of you directly.
As a Gmail or Outlook user, your emails are sent from Google or Microsoft IPs, and some of their users are spammers. And these spammers are responsible of making some of these IPs blacklisted by SORBS Spam.
To conclude, if you're a Gmail or Outlook user, don't panic, at all.
Your sending IP address always changes as it's managed by Gmail or Outlook, and you don't have control on that.
In other words, you can ignore being listed on SORBS Spam if you're using Gmail or Outlook.
Why is my IP Address Listed ?
Sending emails from Gmail, Outlook or any email provider using shared IP addresses
As explained just above, if you send emails using Gmail or Outlook, a lot of their sending IPs are listed on SORBS. And when you send an email from Gmail or Outlook, the sending IP address used to send your email always changes, you're not linked for ever to that IP.
And even if Gmail and Outlook IPs are listed on SORBS Spam Blacklist, it doesn't prevent these two providers to be the best to send your emails to the inbox of your recipients and not in spam.
Again, if you're on Gmail or Outlook, you don't have control and IP addresses always rotate. And it's fine.
For people using other sending solutions, such as SendGrid, Brevo (Sendinblue), or any other that use shared IPs, it means that the sending IP address used to send your emails is also used by other people who use your solution.
In other words, you're not in control as well and the blacklisting may have been triggered by someone else.
You can still ask your provider to be assigned a different shared IP address or switch to a dedicated static IP address. In the latter, you'll be the only one using that IP. That helps protecting your deliverability from the bad behavior of others.
Sending emails to spam traps
SORBS uses spam traps to identify "spammers".
Spam traps are special, confidential email addresses not actively used by individuals but created and maintained primarily by anti-spam organizations such as SORBS.
They're used to catch spammers who send unsolicited emails. These addresses can be publicly available and may end up in compiled and often outdated email lists, sold for marketing purposes.
Any emails sent to these spam traps can result in the sender being labeled as a spammer, as it implies that the sender has not obtained the necessary consent from the recipients.
Open Relay Blocking System
Using an open relay or proxy can compromise email servers by providing unrestricted access to any individual. This poses a security risk and needs to be addressed immediately. SORBS employs an Open Relay Blocking System to identify and block emails sent from open mail relays, which enable anyone to send emails without authentication.
Your IP address can be blacklisted in 'socks.dnsbl.sorbs.net' if it is found to have an open SOCKS proxy. Taking proactive steps can help prevent yourself from being added to that list.
To protect email servers from open relays and proxies, it is crucial to maintain a host list—a comprehensive register of authorized applications and addresses that can access a domain. This proactive measure helps ensure the security and integrity of your email communications.
Compromised Email Servers
Compromised email servers refer to email servers that have been hacked or breached, resulting in unauthorized access to the server and its contents. This can pose various security risks, such as identity theft, fraud, and spam distribution. You have been blacklisted for sending multiple spam emails to numerous recipients. This suggests there may be a security threat present in your IP address or mail server.
To avoid the risk of future unauthorized email transmissions and consequent blacklisting, it is advisable to collaborate with network administrators to effectively block email threats. By staying vigilant and proactive, you can safeguard your email server and maintain seamless email deliverability.
Impact of SORBS Blacklisting on Email Deliverability
If you mostly send emails towards Microsoft or Gmail inboxes, SORBS doesn't directly affect your ability to land in inbox.
As said earlier, the major inbox providers are Google (Gmail and Google Workspace) and Microsoft (Outlook / Office 365 / Hotmail). They own most of the market shares.
They both use their own algorithms to decide if your emails will land in inbox or spam.
Blacklists like SORBS, Spamhaus Zen, SpamCop, Barracuda, UCEPROTECTL3 are services external to Google and Microsoft.
In most cases, Google and Microsoft don’t care about them. They don't take them into account.
Why? Because Google and Microsoft have a much more reliable way to know if you’re a spammer or not.
They prefer analyzing how their users react to your emails: your engagement rate.
In other words, when you send emails to Gmail, Outlook, Hotmail inboxes. These providers check :
- How many openings and clicks you receive
- How many positive replies you get
- How many emails marked as important
- How many spam complaints you receive
- Etc
That's why you need a lot of positive interactions. And that's what an email warm up service does. More information below.
If you send emails to inboxes on smaller ISPs or private mail servers, it can impact your deliverability :
Being listed on SORBS can potentially impact your deliverability if you send emails to email servers or services that take SORBS into account to filter spam. This could include smaller ISPs, enterprise email systems, private email servers, and some web hosting companies. SORBS is also used by some companies to protect their internal email systems from spam and malicious emails.
[IMPORTANT] Run a free spam test now. It takes 1 minute.
Listed on SORBS spam or not, your main priority is to check your deliverability (where your emails land) and take action if needed.
To get your deliverability score and find out where your emails land on the major providers, you can use MailReach’s Free Email Spam Test.
Basically, you simply have to send an email (under real sending conditions) to a list of 31 inboxes given by MailReach and you'll receive a detailed report on your deliverability including all the things you can do to improve your inbox placement.
You get a score out of 10 and a list of checks (content, spam words, links, tracking, blacklists and many more).
Checking Your IP address' Blacklist Status
You have several ways to check your IP address blacklist status.
First, you can check it by performing a free spam test with MailReach. You'll find out where your emails land on the major inbox providers. And you will have a free diagnostic of your email content and sending setup (DNS records, IP address or domain blacklisting, MX, reverse DNS, etc).
Secondly, by checking on the SORBS website using their lookup tool.
And finally, by using other tools such as MXToolbox, a suite of tools to check your DNS, MX records and blacklists.
Delisting Process: Step-by-Step Guide to remove yourself from the Sorbs Spam Blacklist
[for non Gmail & non Outlook users]
If you find your IP address on the SORBS Spam Blacklist, don't panic. You can follow the delisting process to remove your IP address from the blacklist.
As explained above, this process is useful only if you run your own mail server or use a dedicated or static IP address to send your emails.
Here's the process to ask SORBS for delisting :
- Go on SORBS' page to delist an IP address
- You'll be asked to register a new account. Do it.
- Log into your account.
- Click on "Delist An IP Address".
- When prompted, enter your unique IP Address and click "continue".
- A list of IP addresses shows up.
- Locate your specific IP Address and click "proceed" for each instance where your IP Address is listed.
- To finalize, click on the “Get Help/Support” button to generate a support ticket.
- After the ticket has been created, a confirmation message will be sent to you, confirming that your ticket has been successfully opened.
Best Practices for Avoiding Future Blacklisting
1. Minimize your risk of sending emails to spam traps
- Don't buy lists : they can contain spam traps, people with high complaint rates etc. Bad idea.
- Don't collect email addresses all over the internet:
- For marketing / newsletters / transactional emails, your contacts should only come from people who opted in.
- For a cold email sending activity: get your email list from LinkedIn using a scraping tool like Evaboot.
2. Minimize your risk of having spam complaints
- Obtaining explicit consent from recipients before sending them emails and honoring opt-out requests promptly (For marketing / newsletters / transactional emails)
- Providing a clear and easy-to-use unsubscribe link in all emails.
3. Monitor your sender reputation
- Regularly monitoring your IP reputation and deliverability to detect and resolve issues quickly.
- Use a solution like MailReach to help your track your reputation and maximize it. It's a game changer to make sure your emails reach the inbox. See below for more details.
4. Get properly authenticated and secured
- Set up the SPF, DKIM, and DMARC records to demonstrate that you're a legitimate sender.
- For those who have their own mail servers, secure your servers to protect them from malware or bots that send fake emails, which can hijack your IP address and easily cause blocklisting.
Working with Internet Service Providers (ISPs)
Collaborating with Internet Service Providers (ISPs) can play a crucial role in ensuring that your IP address is not blocked by SORBS. By implementing best practices such as authenticating your email domain, maintaining proper IP address allocation, perfecting the opt-in process, and regularly cleaning your email list, you can improve email deliverability when working with ISPs.
By fostering a strong relationship with ISPs and adhering to the recommended practices, you can prevent your IP address from being blacklisted and maintain seamless email communication. Staying proactive and vigilant is the key to avoiding the SORBS blacklist and ensuring the successful delivery of your emails.
Make sure to monitor, raise and maintain your sender reputation with a proper email warmer like MailReach.
To have a great email deliverability and deliver all your emails to the inbox of your recipients, you need to have a good sender reputation.
Your sender reputation is mostly influenced by how your recipients react to your emails.
As said above, the higher the engagement rate you get on your emails, the more likely you are to reach the inbox.
By getting positive interactions to your emails (openings, positive replies, stars, removing your emails from spam) it teaches Google and Microsoft to put your emails in the inbox of their users.
That’s the job of MailReach’s email warm up service : generating a perfect email activity to your inbox by starting conversations with a network of thousands of inboxes.
Each of your warming emails are opened, replied positively, marked as important and removed from spam. It raises your sender reputation and, in turn, your deliverability.
Frequently Asked Questions
How do I get rid of SORBS spam?
If you want to get rid of SORBS spam, the best solution is to contact SORBS directly and ask for delisting. You'll need to provide your IP address and email address in a form on their website, then wait for them to review it and provide further instructions.
Keep in mind that if you're a Gmail, Outlook or any email provider using shared or dynamic allocated IP addresses, you're not in control of that blacklisting.
What is SORBS spam blacklist?
SORBS (Spam and Open Relay Blocking System) is a DNS based block list designed to block emails from IP addresses suspected of relaying spam, phishing, or malware. Being listed on SORBS Spam can impact email deliverability or not depending the type of mailboxes you actually target with your emails.
Google and Microsoft don't take external blacklists like SORBS into account to filter the emails of their users. That means that, if you are listed in SORBS and send emails to Gmail, Outlook or Hotmail inboxes, you won't be penalized because you're listed on SORBS.
But if you target email servers or services that take SORBS into account to filter spam, your deliverability may be affected. This could include smaller ISPs, enterprise email systems, private mail servers, and some web hosting companies.
Is it bad to be blacklisted in SORBS?
It depends what's your email provider and the type of mailboxes used of your recipients.
If you're using Gmail or Outlook, a lot of their dynamically allocated IP addresses are listed on SORBS spam. But these IP addresses always change so you're fine.
On the other side, if you mostly send emails to people using Google (Gmail) or Microsoft inboxes (Outlook, Office 365, Hotmail), then being listed on SORBS spam won't have any negative impact as these two providers don't take SORBS into account to filter the emails.
Does Gmail use SORBS spam?
Gmail doesn't not use SORBS spam to filter the emails. They use their own proprietary algorithms to decide if your emails will land in inbox, spam or promotion tabs.
Gmail uses a much more reliable way to decide where your email will land: by analyzing how their users react to your emails: your engagement rate.
In other words, the more positive interactions you have with your emails (openings, interested replies, emails marked as important and removed from spam), the more likely you are to land in inbox.
This is why, in 2023 and more than ever, using email warm up is a game-changer to land in inbox.
