Are you receiving many emails on Gmail from a single source, despite unsubscribing from their mailing lists? One of the best ways to block spam from such unwanted senders is to blacklist their IP addresses. In a similar vein, you can whitelist an IP address so it doesn’t get blacklisted. This is very useful if some of your important email sources frequently end up in the Spam folder.
Follow the methods below to blacklist or whitelist a given IP address for Gmail. While the blacklisting shown here is specific to Gmail, one of the whitelisting techniques has more universal applications. It will erase an IP address from multiple blacklisting services.
Determining IP Addresses in Gmail
Whether you want to blacklist or whitelist a sender, the first step is to determine the mail server’s IP address. In Gmail, you can find this by opening any email and clicking “show original.”
Scan the “Received” portion of the header section where you should be able to clearly see a sender IP.
Blacklisting any IP Addresses for Gmail
Since it doesn’t allow you access to its mail servers, Gmail has no mechanism to block incoming emails based on their IP addresses. To do this, you will need a third-party service such as Block Sender. It is available as a Chrome/Edge or Firefox extension.
Once the extension is added to your browser, sign in to Block Sender using your Gmail account.
Click “New Block” on the Block Sender dashboard.
In the next step you should see an option to block an email sender based on the IP address. You can decide whether future emails from the source should go to Trash or be deleted directly. This particular service (of blocking email sources by IP addresses) is only available with Plus or Pro paid plans.
Some spam sources do not remain at a permanent IP but rather attack from new IPs assigned across a range. To block them, Mailstrom is a useful service. It lists all the emails from a source, and once you click “Block,” it will identify the IP addresses range, among other things, and ensure that any future emails do not show up in your inbox.
Whitelisting Your IP Addresses
Whitelisting any IP addresses is more time-consuming than blacklisting because of many email filter services linked to webmail accounts. In case your emails are classified as spam by Gmail servers, you will notice a 550 error. Google has a specific sender form to help you ensure deliverability for Gmail users.
If you have a GSuite account, you can easily whitelist multiple IP addresses for Gmail from its Admin console in “Settings for Gmail -> Advanced Settings -> General Settings -> Spam -> Email Whitelist.”
However, in most common examples, the challenge is due to an email server IP landing in one of the critical blacklists. There are two popular web services to check whether you’re facing this issue: MultiRBL and MxToolbox. The second tool to whitelist the IP address that was used in the previous section is used in this example below. The exact blacklist service has been identified. Click “detail” to get more details about the service.
Most email blacklist services have a contact form, chat service, or a simple button to request for a delist, such as this particular example.
To submit a delisting request, you will have to generally create an account with the concerned service.
After you create an account, send a request for whitelisting the specific IP address. It doesn’t take very long to submit this request.
The request for whitelisting will show on a dashboard. It normally takes a few minutes for this request to be processed.
As shown here, the IP address has been removed from Abusix blacklisting service.
The best ways to blacklist or whitelist IP addresses for email servers is to have your own domain and to be able to control your root file. You can learn how to set your own email server on Windows PC.
Do remember there are spammers with thousands of unique IP addresses. So with them, it might be impossible to keep up, but the discussed tool Mailstrom, is useful.