Gmail Spam Filter: How It Works and How to Customize It (2024)

What Gmail Spam Filter Is and How It Works

Did you know that it takes the average person five seconds to identify and delete a spam message? Considering that most office workers receive around 100 emails every day, it’s easy to see just how high the productivity cost of spam really is.

Fortunately, Gmail users are not defenseless against junk, because the Gmail spam filter always has their back. Think of the spam filter for Gmail as a stacked funnel that takes into consideration a number of factors to determine whether an email is legitimate.

To start with, the filter always checks whether the sender’s email address has been blacklisted. If it has, the email is blocked, no matter what. But what about emails from unknown senders? That’s where things get more interesting.

Gmail uses advanced machine learning, which is a type of artificial intelligence. This system constantly learns from the massive amount of emails flowing through Gmail every day. It looks at different factors like where the email comes from, the domain name, and whether users have marked similar emails as spam before. Your actions also play a big role – when you mark an email as spam or not spam, you're helping Gmail learn what you want to see.

Starting February 2024, Gmail is implementing new regulations for bulk senders, those sending over 5,000 messages a day, to enhance email security and reduce inbox spam. These new requirements include mandatory email authentication to confirm the sender's identity, simplifying the unsubscription process to a single click, and enforcing a strict spam rate threshold to minimize unwanted emails.

These changes, a part of Gmail's ongoing efforts to improve user experience, have resulted in a 75% drop in unauthenticated messages, making inboxes more secure and less cluttered.

How to Change Spam Settings in Gmail

As we’ve just explained, the Google spam filter is very complex software that operates effectively with minimal user intervention. However, you can adjust the Gmail spam settings to fine-tune its performance according to your preferences.

Bypass Spam Filters for Messages from Addresses or Domains

For example, you can bypass spam filters for messages from addresses or domains specified in an approved sender list:

1. Sign in to your Google Admin console.
2. Navigate to the main menu and select Apps → Google Workspace → Gmail → Spam, phishing, and malware.
3. On the right side of the screen, look for and select either the Configure button or the Add another rule option.
4. At the top of the new window, just below the Spam section, you'll find a space to type in a unique name for your new rule.
5. Choose Create or edit list located beneath the Options section, but skip past the initial set of options.
6. Under Option to bypass filters and warning banners, select Add address list. Here, you'll need to give your list a specific name. Then, select Add Address and input the email address or domain you wish to whitelist. Ensure the option for Authentication required (received mail only) is disabled.
7. After completing these steps, hit Save and return to the tab where your rule is in progress.
8. Now, click on Use existing list, select the list you just created, and finalize your settings by clicking Save.

Here is how to add an email to your spam list in Gmail:

1. Hover over the list name and click Edit, then click Add.
2. Enter the email address or domain name you want to add.
3. Click Save.

You can repeat these steps to add additional email addresses or domains to the list.

💡 Note: The options described above influence the behavior of the Gmail junk mail filter throughout the entire organizational unit in which the filter is applied. These options take precedence over local Gmail spam filters, meaning that any differing local settings will be overridden.

If you use Gmail primarily for personal emails and don't have access to Google Workspace, you can still adjust how the Gmail junk filter manages emails from new senders. Here's how to avoid Gmail spam filter:

1. Log into your mail account through your preferred web browser.
2. Click on the Settings gear icon at the top right and select See all settings.



3. Navigate to the Filters and Blocked Addresses tab and click Create a new filter.



4. Fill in the necessary fields according to your filtering preferences.
5. After defining the filter criteria, click on Create filter, select Never send it to Spam, and opt for Also apply filter to matching conversations.
6. Finally, click Create filter again to complete the setup.

While setting up individual filters can be complex and time-consuming, tools like Clean Email are often recommended for a more efficient and user-friendly experience.

Mastering Gmail Spam Settings for Email Delivery

No software is perfect, and this is especially true for email spam filters. Despite the numerous improvements Google has implemented over the years, its junk filter is still not flawless. Sometimes it fails to catch a dangerous spam message, allowing it to bypass the Spam folder. Other times, it incorrectly marks legitimate messages as spam, preventing them from reaching the inbox.

If your email messages are constantly getting caught by the spam filters, you should become familiar with the main factors that can impact the deliverability of emails.

Factor 1: Email Content

Do you sometimes read spam emails out of sheer curiosity? If so, you've likely noticed that they often contain numerous grammar and spelling errors. The Gmail email spam filter can analyze email content and flag an email as suspicious if it appears illegitimate. Therefore, it's important to proofread your emails before sending them.

Additionally, you should avoid using common spam trigger words such as 'credit', 'cash', 'reward', 'income', 'passwords', etc. However, the mere presence of a few spam trigger words isn't enough to convince the filter that your emails are junk, so there's no need to obsessively avoid all of them, as that would be nearly impossible.

Factor 2: Domain Name

Gmail maintains a list of malicious domain names that have been blacklisted for sending spam emails. If your email address is associated with a blacklisted domain name, there is a very high chance that the Gmail junk filter will automatically mark all emails from it as spam. To check if your domain name is blacklisted, you can use a blacklist checker such as MX Lookup, which checks against over 100 DNS-based email blacklists.

Factor 3: Email Header

Email headers are hidden code snippets in emails, containing information about the sender, the recipient, the email's route to the inbox, and various authentication details. In Gmail, you can view email headers by selecting 'More' (three vertical dots) and then 'Show original' in any open email message.

Spammers sometimes manipulate email headers to conceal their true identity or to impersonate someone else. Additionally, email headers can become corrupted due to a buggy or misconfigured email client. Therefore, if your messages are frequently caught by the spam filter, consider switching to a different email client.

Factor 4: Attachments

Cybercriminals commonly distribute malware via email attachments, as this method allows them to target thousands of email users with minimal effort. The good news is that all modern email services analyze attachments for malware. However, the downside is that these security mechanisms can sometimes mistakenly categorize legitimate attachments as dangerous. To circumvent this issue, consider sharing files as links through cloud storage services.

Factor 5: Get Whitelisted

The only surefire way to ensure your emails never get caught by the Gmail spam filter is to ask recipients to whitelist your email address. If you're a marketer or run a business, encourage your recipients to add your address to their address book. The spam filter will automatically interpret this action as a clear indication that emails from your address should not be directed to the Spam folder.

Use Clean Email in Addition to Gmail Spam Filter

As mentioned earlier, a mail provider’s spam filter might not catch all junk messages, and this is where Clean Email can be beneficial.

Clean Email, a bulk email organizer, enables you to easily create spam filter rules without altering your Gmail spam settings. This app employs intelligent algorithms to categorize emails. Unlike the Gmail junk mail filter, which differentiates only between legitimate and junk messages, Clean Email can identify various types such as subscription newsletters, social media notifications, unsolicited advertising emails, and more.

Moreover, the app's Screener feature offers a solution for those overwhelmed by unwanted emails from new senders. When enabled, this feature quarantines messages from first-time senders, allowing you to review them without cluttering your inbox.

You can choose to block or approve each sender: blocking stops future messages, while approving allows them direct access to your inbox.

With Clean Email, you can also manage messages in bulk and set it to automate actions, like marking all social media emails as read, and more. This saves time and keeps your inbox focused on important messages. The tool also tracks how many emails are processed by these rules, giving you a quick overview of its effectiveness.

What’s more, the Unsubscriber feature protects against junk by automatically unsubscribing you from unwanted email subscriptions. This is crucial because cybercriminals often steal large email lists for spamming, and sometimes companies sell these lists to spammers.

Protecting your personal information is crucial, especially as data breaches are common across various websites, including banks and retailers. Clean Email's Privacy Monitor proactively checks your email against known breaches and security violations. It alerts you if your information is compromised, suggesting actions like changing passwords or enabling multi-factor authentication, ensuring you stay ahead of potential threats to your data and identity.

To start using Clean Email for free, just sign in with your email address and the current password for your mailbox. The service provides dedicated apps for iOS and Android, ensuring a smooth email experience on mobile devices.

Conclusion

There are several spam settings Gmail users can adjust to minimize junk in their inbox, though these settings have their limitations. Fortunately, third-party solutions like Clean Email exist. This tool enhances the Gmail spam filter by allowing you to effortlessly create automation rules that organize your inbox, helping to boost your productivity.

Related articles:

1. Why are emails going to spam in Gmail?
2. Why Is My Gmail Spam Filter Not Working?

Gmail Spam Filter Settings - FAQs