Is Proofpoint commonly used for corporate email, and how does it affect webmail deliverability issues like blacklisting?
Matthew Whittaker
Co-founder & CTO, Suped
Published 28 May 2025
Updated 15 Aug 2025
7 min read
For many organizations, email is the primary communication channel, making its security and reliable delivery paramount. This is where solutions like Proofpoint come into play. Proofpoint is widely recognized as a major player in corporate email security, providing advanced threat protection, compliance, and archiving services to businesses of all sizes, from large enterprises to smaller companies. Their robust platform helps protect against phishing, malware, spam, and other email-borne threats.
The core function of Proofpoint's email security gateway is to act as a crucial gatekeeper for incoming and outgoing emails. It scans messages for suspicious content, malicious attachments, and indicators of spam or phishing attempts before they reach the recipient's inbox. While this is essential for corporate security, it also significantly impacts how emails from external senders, including those from webmail providers like Gmail or Yahoo, are received.
This powerful filtering capability means that if your emails are intended for recipients within organizations that use Proofpoint, your deliverability depends heavily on their system's assessment of your sending practices. Even if your emails generally land in the inbox for standard webmail users, they might face challenges when passing through corporate-grade filters.
Proofpoint is indeed commonly used for corporate email, with a significant presence in the enterprise sector. Companies adopt Proofpoint for its comprehensive suite of services that go beyond basic spam filtering. It offers solutions for email encryption, data loss prevention (DLP), and advanced threat protection (ATP), making it a cornerstone for many corporate cybersecurity strategies. You can find more information about its functionalities on Lumifi's explanation. Because of its widespread adoption, understanding how Proofpoint operates is vital for anyone involved in email marketing or sending transactional emails.
Their solutions primarily focus on protecting corporate inboxes from external threats, which means they maintain their own proprietary blocklists (or blacklists) based on their threat intelligence. These internal lists are dynamic and react quickly to new spam campaigns, phishing attempts, and other malicious activities. Consequently, if your sending IP or domain is flagged by Proofpoint's systems, it can lead to significant deliverability challenges when sending to their protected clients.
It's important to remember that Proofpoint's filtering isn't necessarily about general email deliverability issues with webmail providers, but rather specifically about how corporate email security policies and systems interact with your sending infrastructure. A listing on a Proofpoint internal blacklist (or blocklist) primarily impacts delivery to businesses using their services, rather than consumer-facing webmail directly.
How Proofpoint influences email deliverability and blacklists
When your sending IP address or domain gets listed on a Proofpoint blocklist, it means that emails originating from that source will likely be rejected or heavily filtered by organizations using Proofpoint. This can manifest as emails not being delivered at all, receiving deferral messages, or being routed directly to spam or junk folders within the corporate environment. The impact can be substantial, as corporate email addresses often represent key communication points for businesses.
Understanding Proofpoint's blocklist impact
Proofpoint maintains its own proprietary blocklists, which are distinct from public blacklists (or blocklists) like Spamhaus or SORBS. Being listed on a Proofpoint blocklist specifically affects delivery to Proofpoint-protected domains. For more on the general concept of email blocklists, refer to ActiveCampaign's guide.
One common scenario that leads to a Proofpoint blacklist (or blocklist) entry is sending unwanted or suspicious email traffic. This includes anything from inadvertent spamming due to a compromised account to deliberate bulk mailings that violate their policies. The proprietary nature of Proofpoint’s lists means you won't always find your IP on public blocklist checkers, making direct communication or monitoring specifically for Proofpoint issues essential. It's also worth noting that Proofpoint's systems are constantly adapting to new threats, so what might have passed through yesterday might be flagged today.
Furthermore, Proofpoint plays a significant role in email authentication for organizations, particularly for services like Outlook domains. A misconfigured SPF, DKIM, or DMARC record can lead to emails being rejected or flagged by Proofpoint, even if the content itself is legitimate. This is a critical aspect, as proper authentication signals trust to email filters.
Navigating Proofpoint blacklists (blocklists) and delisting
Getting delisted from a Proofpoint blacklist (or blocklist) can sometimes be a lengthy process. Unlike some public blocklists that automatically delist after a certain period, Proofpoint often requires direct engagement to resolve the issue. This usually involves identifying the root cause of the listing, remediating it, and then submitting a delisting request to Proofpoint’s support. You might find yourself needing to contact Proofpoint support directly.
Common causes of Proofpoint blocks
Compromised accounts: Accounts sending spam or phishing emails.
Spam complaints: High rates of users marking your emails as spam.
Malware distribution: Sending emails with malicious attachments or links.
Poor sender reputation: General indicators of untrustworthy sending practices.
Strategies for delisting
Identify the cause: Use logs and feedback to pinpoint why your IP or domain was listed. This might involve checking your domain reputation more broadly.
Request delisting: Follow Proofpoint's official process for delisting. Provide clear evidence of remediation.
Monitor continuously: Keep an eye on your sending reputation to prevent future listings.
One practical step to improve your standing, especially if you're using a shared IP from a provider like SendGrid, is to ensure your reverse DNS (rDNS) is properly configured and points to your domain or brand. This helps differentiate your sending from other users on the same IP range and builds trust with receiving filters, including Proofpoint's. Setting a unique rDNS can be a significant factor in how Proofpoint views your IP reputation.
Example of an rDNS recordDNS
11.142.72.149.in-addr.arpa. IN PTR mail.yourdomain.com.
It’s also important to acknowledge that Proofpoint, like other major email security vendors, can affect deliverability to webmail providers that also employ their solutions or rely on their data. For instance, if Proofpoint shares threat intelligence with a webmail provider, a blocklist entry on Proofpoint could indirectly impact your deliverability to that webmail service. This is particularly relevant when you encounter email delivery issues with Proofpoint and services like Apple Mail (or iCloud email addresses) simultaneously. Understanding why your emails are being blocked by Apple Mail often involves looking at Proofpoint.
Views from the trenches
Best practices
Always implement proper email authentication including SPF, DKIM, and DMARC to build trust with Proofpoint and other filters.
Regularly review your email sending practices to ensure compliance with anti-spam policies and maintain a clean sender reputation.
If using a third-party sending service, inquire about dedicated IP options and the ability to configure your own rDNS.
Set up monitoring for Proofpoint-specific blocklists, if available, or closely track bounce messages for deferrals.
Common pitfalls
Neglecting rDNS configuration for shared IPs, which can make your sending appear less legitimate to Proofpoint.
Underestimating the time and effort required for delisting from Proofpoint's proprietary blocklists, which are not public.
Assuming that a clean record on public blocklists means you are safe from Proofpoint's internal filtering.
Not having a clear process for handling security incidents that could lead to your domain or IP being compromised.
Expert tips
Proactively ensure high email engagement and low complaint rates to positively influence your sender reputation with Proofpoint.
When dealing with a blocklist, communicate transparently with Proofpoint and provide detailed information about your remediation efforts.
Regularly audit your email lists to remove inactive or problematic addresses, reducing the risk of hitting spam traps.
For critical corporate communications, consider a dedicated IP address to better control your sending reputation.
Marketer view
Marketer from Email Geeks says that Proofpoint is very commonly used for corporate email, indicating its widespread adoption in business environments.
2020-11-20 - Email Geeks
Marketer view
Marketer from Email Geeks says that Proofpoint's definition might vary depending on its specific product suite, as it offers various email security solutions.
2020-11-20 - Email Geeks
Maintaining deliverability in a Proofpoint world
Proofpoint’s extensive use in corporate environments means that any organization sending emails to businesses must consider its impact on deliverability. While it doesn't directly manage consumer webmail inboxes, its blocklists (blacklists) and filtering mechanisms can significantly hinder email delivery to a vast number of corporate recipients. Maintaining a strong sender reputation and adhering to best practices are crucial for navigating this landscape.
Proactive measures, such as ensuring proper email authentication (SPF, DKIM, DMARC), monitoring your sending reputation, and promptly addressing any issues that could lead to spam complaints or security flags, are your best defense. If you find your emails blocked, a structured approach to identifying the cause and engaging with Proofpoint support is often necessary. Remember that Proofpoint's systems are designed to be highly responsive to threats, which means a clean sending history is your strongest asset.
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