Why are my emails to Proofpoint recipients not bouncing, but not arriving?

If you receive a '250 OK' SMTP response, Proofpoint has accepted your email but likely quarantined it or sent it to a spam folder. This often happens due to sender reputation, content analysis, or recipient-specific filtering rules, rather than an outright rejection.

Can I get Proofpoint to whitelist my domain directly?

No, Proofpoint does not offer direct safelisting (whitelisting) to external senders. Any adjustments to filtering or whitelisting must be initiated by the recipient's IT department, as they are Proofpoint's customers.

What should I check in my Google Workspace mail logs?

Look for the SMTP response code you receive when sending to Proofpoint -protected domains. A '250 OK' means the email was accepted, while a '4xx' indicates a temporary deferral and a '5xx' means a permanent rejection or bounce. This helps determine if the issue is with acceptance or post-acceptance filtering.

How important are SPF, DKIM, and DMARC for Proofpoint deliverability?

SPF, DKIM, and DMARC are critical . Proofpoint relies heavily on these email authentication protocols to verify sender legitimacy. Misconfigurations or failures can significantly reduce your sender reputation and lead to emails being blocked or quarantined. DMARC monitoring with Suped can help identify and resolve these issues.

What role does recipient IT play in resolving Proofpoint blocks?

The recipient's IT department is your most direct channel for resolution. They have access to their organization's Proofpoint dashboard and logs, allowing them to identify why your emails are being filtered and to adjust their settings or policies to ensure delivery. You may need to contact Proofpoint about IP blocks through their internal channels.

Why are my emails blocked by Proofpoint? - Troubleshooting - Email deliverability - Knowledge base

It can be incredibly frustrating when your important emails aren't reaching their intended recipients, especially when those recipients rely on a robust security solution like Proofpoint. Many businesses, including those using Google Workspace for their daily communications, find themselves in this predicament. The challenge is often compounded when emails don't bounce back, leaving you wondering if they're simply vanishing into the digital void.

When emails are not bouncing, it indicates that

Proofpoint has likely accepted the message but then filtered it into a spam folder or quarantine, rather than rejecting it outright. This situation can be particularly difficult to troubleshoot without visibility into the recipient's email system. Understanding what causes Proofpoint to block or defer emails and how to approach the resolution is key to improving your deliverability.

This guide will walk you through the common reasons why

Proofpoint might be blocking your emails and outline practical steps you can take to get your legitimate communications delivered. We'll explore examining mail logs, ensuring proper email authentication, addressing sender reputation, and navigating the process of working with recipient IT teams.

Checking your mail logs for clues

When your emails aren't reaching inboxes, the first place to look is your own mail logs. If you're using

Google Workspace, the administrator has access to detailed information about both inbound and outbound messages. This includes the SMTP response codes from the receiving server, which are crucial for diagnosis.

A common response you might see is a 250 OK message. This response means the receiving server (in this case,

Proofpoint) has accepted the email for delivery. If you receive a 250 OK but the email still doesn't reach the inbox, it strongly suggests the message has been accepted but then quarantined or moved to a spam folder due to

Proofpoint's internal filtering rules. These rules can be based on various factors, including content, sender reputation, or specific policies set by the recipient's IT department. Without a bounce, it's not an outright rejection, but rather a soft block or quarantine.

Understanding SMTP response codes

SMTP response codes provide critical clues. Here’s a quick overview:

2xx Success Codes: The server accepted the command or is starting a mail transaction. A 250 OK means the email was accepted for delivery.
4xx Transient Failure Codes: The server encountered a temporary problem, such as being too busy or lacking disk space. The sender should try again later (e.g., a deferred email).
5xx Permanent Failure Codes: The server encountered a permanent error, meaning the email will not be delivered (e.g., recipient not found, server policy violation). This results in a bounce message.

Email authentication and sender reputation

Effective email authentication is fundamental to ensuring deliverability. SPF, DKIM, and DMARC records act as digital signatures, verifying that your emails are legitimate and haven't been tampered with.

Proofpoint, like other major email security gateways, heavily relies on these protocols to assess incoming mail. If your authentication is misconfigured or failing, even plain text, day-to-day emails can be flagged as suspicious.

I often see issues where organizations haven't fully implemented DMARC or have errors in their SPF or DKIM records. Even if your emails are sent from

Google Workspace, ensuring these are correctly configured for your sending domain is vital. A strong DMARC policy at 'quarantine' or 'reject' helps to prevent spoofing and builds trust with receiving mail servers. Using a DMARC monitoring tool like Suped can give you the visibility you need to identify and fix these issues.

Scenario: weak authentication

SPF record missing or misconfigured, not listing all authorized sending IPs.
DKIM signatures invalid or absent, failing cryptographic verification.
DMARC policy not enforced (p=none) or misaligned, allowing spoofing attempts.

Proofpoint's response

Increased spam score: Emails more likely to be flagged as spam.
Quarantine or rejection: Depending on the severity and recipient's policies.
Loss of trust: Negatively impacts your domain and IP reputation over time.

Regularly monitor your DMARC reports to identify any authentication failures. Suped's DMARC monitoring platform makes it easy to visualize these results and quickly pinpoint authentication problems that

Proofpoint might be using to filter your emails.

Sender reputation and content analysis

Beyond authentication,

Proofpoint's filtering is heavily influenced by your sender reputation. This reputation is built on various factors, including the history of your sending IP address, the domain's age and activity, and the content of your emails. Even if you're sending plain text emails for day-to-day communication, if your IP or domain has a poor reputation,

Proofpoint might still block or quarantine your messages. This is particularly true if you are using shared IP addresses, where the actions of other senders can negatively impact your deliverability, as discussed in a Hacker News discussion.

Content can also be a silent killer. Even plain text emails can contain elements that trigger spam filters. This could include certain keywords, suspicious formatting (even if unintentional), or even malicious links hidden in signatures or attachments. A Reddit thread highlights how even seemingly innocuous elements can lead to blocking.

Proofpoint's advanced threat protection analyzes email content deeply for any signs of phishing, malware, or spam characteristics.

Factor	Description	Impact on deliverability
IP reputation	History of the sending IP address, especially on blocklists (blacklists). Can be an issue if your IP is listed on Proofpoint.	High likelihood of rejection or quarantine. You might need to resolve IP blocklists.
Domain reputation	Perception of your domain based on email practices. Poor engagement or spam complaints can damage it.	Emails may land in spam or be blocked outright. Impacts brand trust.
Content analysis	Email content scanned for spammy phrases, malicious links, or suspicious attachments. This includes acceptable use policy or content violations.	Emails quarantined or marked as spam, even if authentication passes.

To effectively combat these issues, implement a strong DMARC policy and continuously monitor your sending reputation. Tools like Suped's blocklist monitoring can help you stay aware of your standing across various blocklists (or blacklists) and quickly address any listings.

Working with the recipient's IT department

The most effective way to resolve

Proofpoint blocking issues when emails are accepted but not delivered is to work directly with the recipient's IT department.

Proofpoint itself does not offer direct safelisting to external senders. Their role is to support their customers, meaning the control over email filtering ultimately lies with the company receiving the emails. This means they need to file a support request with Proofpoint if they are not getting mail they want.

The IT team managing the recipient's

Proofpoint instance can investigate why your emails are being quarantined. They can check their internal logs and see the specific reasons

Proofpoint is flagging your messages. This is the most direct path to resolution. If local offices cannot assist, escalating the request to their headquarters' IT department is necessary, as filtering policies are often managed centrally. Remember,

Proofpoint will not override their customer's preferences.

Tips for engaging recipient IT

Provide all details: Include sender and recipient email addresses, timestamps, and any SMTP codes you have.
Emphasize business value: Clearly explain why these emails are critical for their operations.
Request a specific action: Ask them to check their Proofpoint quarantine or spam logs for your emails.
Be persistent: Bureaucracy can make this process slow, but consistent, polite follow-up is important.

Optimizing your own sending practices

While recipient IT engagement is crucial, you should also ensure your own email infrastructure is optimized. Confirm that your domain's SPF and DKIM records are correctly configured, and that you have an active DMARC policy in place, preferably with a policy of p=quarantine or p=reject. This demonstrates to mail filters like

Proofpoint that you are serious about email security and prevents unauthorized use of your domain.

Furthermore, review your email content for anything that might be misinterpreted as spam. Even plain text emails can contain elements that trigger filters. Avoid excessive capitalization, exclamation points, or overly promotional language in day-to-day communications. If you are experiencing deliverability issues with Proofpoint and emails are not bouncing, consider sending a test email to a deliverability tester to get insights on how various filters perceive your messages.

Views from the trenches

Best practices

Always begin by checking your own email logs. A '250 OK' indicates acceptance, shifting the problem to recipient-side filtering or quarantine.

Ensure proper SPF, DKIM, and DMARC setup. Strong email authentication is fundamental for gaining trust with security gateways like Proofpoint.

Monitor your DMARC reports regularly using a platform like Suped to identify authentication failures and improve your email deliverability.

Maintain a healthy sender reputation by avoiding spikes in email volume, managing bounce rates, and securing your sending infrastructure.

When contacting recipient IT, provide specific details like sender, recipient, timestamp, and any relevant mail log entries to help their investigation.

Common pitfalls

Assuming a 'no bounce' means successful delivery, when it often means emails are quarantined by Proofpoint or sent to spam.

Attempting to get Proofpoint to whitelist your domain directly; they primarily support their customers, not external senders.

Overlooking subtle content issues in plain text emails, such as hidden links or unusual formatting, that can trigger spam filters.

Not escalating issues to the recipient's headquarters IT department if local offices cannot resolve email blocking problems.

Failing to review and update SPF and DKIM records when making changes to your email sending infrastructure.

Expert tips

Use a DMARC monitoring tool like Suped to gain immediate visibility into your email authentication status and identify potential issues that Proofpoint might detect.

For complex Proofpoint blocking scenarios, focus on building a case for the recipient's IT team by demonstrating your compliance with email best practices.

If using Google Workspace, leverage the administrative tools to analyze mail flow and identify any rejections or deferrals before engaging with recipients.

Regularly check if your sending IP or domain is listed on any public or private blocklists, and work to delist it promptly.

Educate your internal teams on email best practices to maintain a consistent sending reputation and avoid accidental triggers for spam filters.

Expert view

Expert from Email Geeks says: If a '250 OK' is received, Proofpoint has accepted the email, indicating it's likely being quarantined or filtered by internal rules, possibly due to a CLX score or manual configuration. This means the next step should be to investigate the recipient's side.

July 12, 2024 - Email Geeks

Expert view

Expert from Email Geeks says: Proofpoint does not offer any type of safelisting for external senders. If your emails are legitimate business communication, the recipient's IT department must initiate a support request with Proofpoint to adjust their filtering settings.

July 12, 2024 - Email Geeks

The path forward

Dealing with

Proofpoint blocking your emails can be a multifaceted challenge, especially when there are no bounce messages. The key takeaway is that when

Proofpoint accepts your emails (indicated by a 250 OK in your logs), the subsequent filtering occurs within the recipient's system. Your primary strategy should involve a combination of internal infrastructure optimization and collaborative engagement with the recipient's IT team.

Start by thoroughly checking your

Google Workspace mail logs and ensuring your SPF, DKIM, and DMARC records are impeccably configured. Utilizing DMARC monitoring through a tool like Suped will provide invaluable insights. Then, arm your client with the necessary information to approach their recipient's IT department, stressing the business importance of these communications and providing specific details for investigation. By tackling these issues systematically, you can significantly improve your email deliverability through

Proofpoint protected domains.