Why is Proofpoint blocking my Sendgrid IP address and how can I resolve it?
Summary
What email marketers say12Marketer opinions
Email marketer from DigitalOcean suggests setting up a reverse DNS (rDNS) record for your sending IP address. This helps build trust with receiving mail servers and verifies that the IP is associated with your domain.
Email marketer from Email Vendor Selection notes the importance of checking ESP reputation and deliverability before choosing an ESP. Advises checking several sources and comparing them to get a full understanding
Marketer from Email Geeks shares that the moral of the story is that not all ESPs are created equal, nor does their level of equality remain the same over time. He also mentions that he pinged the Proofpoint team to facilitate a speedier response/remediation.
Email marketer from Reddit explains that new Sendgrid IPs often come with pre-existing reputation issues. They share that it takes time to build a good reputation even with a dedicated IP, and some providers score at the ASN level.
Marketer from Email Geeks advises to check the reputation of an ESP before switching to them. Mentions people in the thread could be consulted and that deliverability consultants should be able to guide you.
Email marketer from Stack Overflow suggests ensuring proper email authentication (SPF, DKIM, DMARC) is set up correctly to improve sender reputation and avoid being flagged as spam.
Email marketer from Litmus suggests monitoring sender reputation using tools like Google Postmaster Tools to identify issues and take corrective actions.
Email marketer from Gmass suggests checking the content for anything that could trigger spam filters such as overuse of certain keywords, or poor HTML formatting.
Email marketer from MXToolbox recommends checking your IP against various blacklists using their tool to identify if your IP has been listed. It advises contacting the blacklist providers to request delisting.
Email marketer from Email on Acid emphasizes the importance of list hygiene. Regularly clean your email list to remove invalid or inactive addresses to maintain a good sender reputation.
Email marketer from Postmark advises to diagnose your sending health using tools available on your Postmark dashboard or similar tools provided by Sendgrid.
Email marketer from Mailjet advises reaching out to Proofpoint's postmaster email address (postmaster@proofpoint.com) with details of the issue and requesting a delisting. Provide all necessary information about your sending practices and authentication setup.
What the experts say3Expert opinions
Expert from Word to the Wise discusses the importance of understanding why you are on a blocklist before requesting removal. If Proofpoint is blocking your Sendgrid IP, they advise investigating the cause (spam complaints, poor list hygiene) and fixing the underlying issue to prevent future blocking.
Expert from Email Geeks explains that DMARC had nothing to do with the Proofpoint IP blocking issue, and the delivery issue faced was because Proofpoint had the IP blocked.
Expert from Spam Resource explains that sender reputation, influenced by factors such as spam complaints, blacklist listings, and email authentication, plays a significant role in deliverability and can lead to blocking by services like Proofpoint. They recommend monitoring your reputation and addressing any negative signals promptly.
What the documentation says4Technical articles
Documentation from Sendgrid outlines the importance of warming up a dedicated IP address gradually. It says to start with low volumes and increase gradually, while monitoring deliverability to ensure good reputation.
Documentation from DMARC.org advises implementing DMARC policies gradually. Start with 'p=none' to monitor, then move to 'p=quarantine' or 'p=reject' after observing results and ensuring legitimate mail is properly authenticated.
Documentation from Proofpoint states that senders can be blocked due to various reputation factors. Suggests checking the Proofpoint Sender Reputation service and contacting postmaster@proofpoint.com for delisting requests.
Documentation from RFC explains to ensure compliance with SMTP standards. This includes correctly formatted headers and proper use of HELO/EHLO commands, which can impact deliverability.