A list of IP addresses that are known to send unsolicited or unwanted emails.
A deny list (some services use the term, "blacklist" or "blocklist") is a list of IP addresses that have been detected sending unsolicited and unwanted emails. Inbox service providers (like Gmail, Microsoft, Yahoo, and AOL) and enterprises use deny lists to identify and filter illegitimate mail streams. Specific sending domains, in addition to sending IPs, can also be added to a deny list.
All major ISPs use some form of deny listing service to protect their customers from malicious emails, although the deliverability impact can vary depending on the service that lists the IP. If you find that your IP address is on the deny list of one the many legitimate services, then submit a delisting request.
SendGrid keeps a close eye on our IP’s, and we try as quickly as possible to resolve any issues with deny lists. However, getting your IP off the deny list often requires the user sending the mail to contact the ISP.
Many SendGrid customers send their mail using SendGrid’s shared IP addresses. For many senders, shared IP addresses help remove the burden of warming up a new dedicated IP address. Shared IP addresses are also a great option for senders who have sporadic or unpredictable sending cadences or senders who don’t send large volumes of email because these two behaviors can make it difficult to establish a consistent reputation on a dedicated IP.
When on a Free or Essentials plan, your account is using shared IP pools-you are sharing IP addresses with many other customers, and there is the potential for one of these other customers to cause a shared IP address to end up on a deny list.
SendGrid closely monitors the health of our shared IP pools. This includes monitoring for shared IPs that are added to reputable deny lists. When we detect that a shared IP has been added to a deny list, we will analyze the deliverability from that IP address and determine if the listing is causing measurable deliverability issues. If we detect issues, we will mitigate the listing.
It is important to note that shared IP addresses, like dedicated IP addresses, will frequently get listed and then delisted by a number of deny lists. Even senders with impeccable sending practices will find themselves on a deny list at some point. The reality is that whether you use shared IP addresses or dedicated IP addresses, deny lists are simply a cost of doing business over email.
Please also note that SendGrid is unable to move your account to a new IP pool because one or more IPs in a shared IP pool is on a deny list.
We ask that our dedicated IP plan users make the initial delisting request if they discover their SendGrid IP on a deny list. SendGrid is happy to step in and assist with these delisting requests if the listing service requires the IP administrator to take action, or if the delisting form is too complicated.
If a sending domain (and not the IP address) is blocked, that domain’s controller is responsible for handling the delisting request.
Below are links to the delisting forms used by the more popular external deny listing services: - AOL - AT&T - email email@example.com - Barracuda - Comcast - Google - Invalument - Manitu - McAfee - Mimecast - Office 365 - SORBS - SpamCop - Spam Rats - Spamhaus - SURBL - Trend Micro - URIBL - Yahoo
- Gmail Email Sender Guidelines
- Yahoo Email Sender Guidelines
- Hotmail/Outlook/Live Bulk Email Sender Guidelines
- AOL Bulk Email Sender Guidelines
If you are sending mail using these guidelines and still have problems delivering email to those email providers, you can contact the ISP support by the following URL:
If a listing service ever asks you pay a fee for a delisting request, or if they say that they do not accept delisting requests, then you should not waste your time or money trying to get your domain/IP delisted because these services are rarely, if ever, used by ISPs.
Looking for customized expert advice to improve your email program? Our team of email experts can help you create a plan to ensure you're optimizing your email delivery and engagement, and avoiding future issues like deny lists. Learn more on our Expert Services page.