What Is the Received Header in Email?
Understanding Received headers and email routing
Table of Contents
What Is the Received Header in Email?
The Received header in email is a header field added by each email server that handles an email message during delivery. Each server adds a Received header containing information about when and how it received the email, including server name, IP address, timestamp, and processing details.
Multiple Received headers show the complete path an email took from sender to recipient, listed in reverse chronological order (most recent server first). Received headers are essential for tracking email routing, identifying delivery delays, troubleshooting delivery issues, and understanding the email delivery path.
Analyze Received headers using our email header analyzer to track email routing, visualize the complete routing path, and troubleshoot delivery issues.
Received Header Structure
Header Format
Received headers typically follow this format: Received: from server-name (IP-address) by receiving-server with protocol; timestamp
Header Components
- from: Sending server name and IP address
- by: Receiving server name
- with: Protocol used (SMTP, ESMTP)
- id: Message ID at this server
- for: Final recipient address
- timestamp: When server received the email
Multiple Headers
Emails typically have multiple Received headers, one for each server that handled the message. Headers are added in order, with the most recent server's header appearing first.
Routing Information
Received headers provide complete routing information:
Server Path
Received headers show every server an email passed through, from the original sending server to the final receiving server.
IP Addresses
Headers show IP addresses of servers, useful for identifying blacklisted IPs, routing issues, or server problems.
Timestamps
Each Received header includes a timestamp showing when that server received the email, allowing calculation of delays between servers.
Protocol Information
Headers show which protocols (SMTP, ESMTP) were used for communication between servers.
Using Received Headers
1. Track Email Routing
Read Received headers from bottom to top (oldest to newest) to trace the email's complete path from sender to recipient.
2. Identify Delays
Compare timestamps in Received headers to identify where delays occur in the delivery path.
3. Verify Server Path
Verify that emails are taking expected routing paths and not being misrouted or delayed unnecessarily.
4. Troubleshoot Issues
Use Received headers to identify which server in the path is causing delivery problems or delays.
Troubleshooting with Received Headers
Received headers are invaluable for troubleshooting:
1. Delivery Delays
Large time gaps between Received headers indicate delays. Identify which server or network segment is causing slow delivery.
2. Routing Problems
Unexpected servers in Received headers may indicate routing misconfigurations or DNS issues.
3. Server Issues
Missing or malformed Received headers may indicate server problems or email client issues.
4. Blacklist Checks
IP addresses in Received headers can be checked against blacklists to identify reputation issues.
5. Extract and Analyze
Use our email header analyzer to extract and analyze Received headers with visual routing path display for troubleshooting.
