SendGrid uses a dedicated IP address to send high-volume campaigns. This guide shows you how to prevent automatic replies (like Out of Office messages) from being sent back to your organization.
Before You Begin
You need:
- Admin access to your Proofpoint console
- Your dedicated IP address (provided during SendGrid setup or available from support@contactmonkey.com)
Why This Configuration Is Needed
ContactMonkey suppresses auto-replies by adding the X-Auto-Response-Suppress header to outbound emails. Proofpoint inspects inbound mail before delivery and, in some configurations, strips or rewrites custom headers it does not recognize. When this happens, the suppression signal is removed before the email reaches the mailbox and auto-replies are sent as usual.
The fix is to create a Proofpoint rule that re-inserts the header on inbound mail from your dedicated IP address.
Create a Header Rule in Proofpoint
- Sign in to your Proofpoint admin console
- Open the rule configuration area for inbound mail (location varies by Proofpoint product)
- Create a new rule and name it (example: "Auto-Reply Suppression for ContactMonkey")
- Under the rule condition, select the following:
- Condition type: Sender IP address
- Operator: matches or is in range
- Enter your dedicated IP address
- Under the rule action, select the following:
- Action type: Add header (or Insert header, depending on Proofpoint version)
- Header name:
X-Auto-Response-Suppress - Value:
OOF, DR, RN, NRN
- Enable the rule and save your changes
Note: The exact menu names and field labels vary between Proofpoint Essentials and Proofpoint on-Demand. If you cannot locate these options, contact Proofpoint support and reference their guide on Best Practices for Using a Third-Party Anti-Phishing Vendor to Test Employees, which uses the same rule pattern.
Test Your Configuration
Send a test email to verify the rule works correctly:
- Send an email using the Send & Track button in ContactMonkey (not Send Test)
- Ensure your email uses Individual tracking
- Confirm no auto-replies are received
What the Rule Does
The X-Auto-Response-Suppress header prevents these automatic responses:
- OOF: Out of Office messages
- DR: Delivery Receipts
- RN: Read Notifications
- NRN: Non-Read Notifications
By having Proofpoint add this header to mail from your dedicated IP, you ensure the suppression signal reaches recipient mailboxes even if upstream filtering would otherwise remove it.
Important Notes
- This rule only applies to emails sent using SendGrid tracking
- Emails sent with Overall tracking are not affected by this rule
- Verify your dedicated IP address is correct before saving the rule
- This configuration does not affect other email functionalities