How can I check which companies are sharing my IP address for email sending?
Summary
What email marketers say10Marketer opinions
Email marketer from SparkPost Blog shares that using a shared IP address can expose your email sending reputation to the activities of other senders on that IP. Monitoring IP reputation is important.
Email marketer from Gmass says if you are worried about the IP reputation of others, that you should upgrade to a dedicated IP
Email marketer from Email Geeks explains that deliverability monitoring platforms often allow you to see other senders sharing an IP via a spam trap network. This can confirm whether your ESP has you on a bad pool.
Email marketer from Quora emphasizes that a good ESP should be transparent about who shares your IP. Suggests directly asking the ESP for information about other users on the same IP.
Marketer from Email Geeks explains that unless the ESP is a 'cesspool', sharing IPs is irrelevant. He states that properly configured authentication will earn senders and their emails the reputation they deserve.
Email marketer from DNSchecker explains that using their tool you can view the DNS history of an IP address to see which domains were associated with it in the past, this will help to see if there were dodgy domains previously using the IP.
Email marketer from Neil Patel's Blog explains that a reverse IP lookup can show which domains are associated with a specific IP address, potentially revealing other companies using the same IP.
Email marketer from Reddit shares that some online tools can show 'neighbors' on a shared IP, revealing other domains hosted on the same IP. Suggests searching for 'shared IP neighbors' tools.
Email marketer from StackExchange shares that if your IP ends up on a blacklist, it might be due to the actions of another sender sharing the same IP. Checking blacklists can indirectly reveal if there are problematic users on the IP.
Email marketer from Mailjet Blog responds that regularly checking your IP address's reputation using online tools helps identify if other senders on the same IP are negatively impacting your deliverability.
What the experts say5Expert opinions
Expert from Email Geeks shares that senderscore.org can sometimes reveal other domains sharing an IP address. He suggests plugging the IP into senderscore.org to see associated domains.
Expert from Spam Resource, John Levine, explains that you can perform a reverse DNS lookup on your IP address. This will show you the domain names associated with that IP, which can help you identify other entities sharing it.
Expert from Email Geeks shares that she is working with an EU ESP and seeing more IP based blocking with local country broadband providers.
Expert from Word to the Wise, Laura Atkins, explains that actively monitoring your IP address's reputation using tools like those provided by Sender Score or Talos can give you insights into the overall health of the IP and whether the behavior of other users on that IP might be affecting you.
Expert from Email Geeks shares that she is seeing an increase in IP-based blocking, especially with EU providers, and mentions a case of a shared IP being blocked at Orange.
What the documentation says4Technical articles
Documentation from DigitalOcean explains that reverse DNS records (PTR records) can be used to identify the domain names associated with an IP address, helping determine who else might be using the same IP.
Documentation from MXToolbox explains that their reverse IP lookup tool can show you all the domain names that are hosted on a particular IP address.
Documentation from Google Support explains that monitoring your IP's reputation is critical for ensuring emails reach Gmail users. They also specify that a low reputation can lead to delivery issues.
Documentation from Microsoft answers question about sender reputation, explaining that monitoring your IP and domain reputation is vital for reaching Outlook users and offers tools for checking this.