Email at Scale 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 the Mimecast Administration Console
- Your dedicated IP address (provided during Email at Scale setup or available from support@contactmonkey.com)
Why Mimecast Requires a Different Approach
Mimecast intercepts and processes emails before they reach your Exchange server. This means mail flow rules created in Exchange will not apply to emails screened by Mimecast. Instead, you must create a Custom Header Policy in Mimecast to suppress automatic replies.
Create a Custom Header Policy in Mimecast
Policy Details
- Name: Suppress Automatic Replies for Specific IP Address (or similar)
- Description: Optional
-
Custom Header Name:
Auto-Response-Suppress -
Custom Header Value:
-
ALLto suppress all automatic replies, or - A specific value if you only want to suppress certain reply types
-
- Policy Status: Enabled (toggled on)
Select Who the Policy Applies To
- Bidirectional: Unchecked
- Allow policy overwrite: Unchecked
Sender and Recipient Rule
- From: Domain
-
Domain: Email at Scale authenticated sender’s domain
-
Example:
em2332.company.com - To: Everyone
-
Example:
Source IP Ranges
- Hostname or IP: The dedicated sending IP address
Test Your Configuration
Send a test email to verify the policy 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
Important Notes
- This policy only applies to emails sent using Email at Scale tracking
- Emails sent with Overall tracking are not affected by this policy
- Verify both your dedicated IP address and authenticated sender domain are correct before saving the policy
- The policy may take a few minutes to propagate after creation