Definition
Received headers record the path, times and servers. They are invaluable for debugging bounces and delays.
Best Practices
- Read Received headers from bottom to top to follow the path.
- Compare timestamps to find delivery delays.
- Use them to confirm authentication and relay changes.
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Related Glossary Terms
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Alt Text
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AOL Mail for Email Marketers
AOL Mail is a legacy email provider with specific deliverability requirements and rendering quirks, now operating as part of the Yahoo+AOL network under shared infrastructure.
Email Authentication Protocols
Email authentication protocols are technical standards that verify the identity of an email sender, helping mailbox providers distinguish legitimate mail from spam and phishing.
BIMI
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Bounce Classification
Bounce classification uses SMTP codes (550, 551, 552, 553, 554, 450, 451, 452) and enhanced status codes to categorise permanent and transient delivery failures.
Frequently Asked Questions
A hop-by-hop trace added by mail systems as a message routes.
The oldest hop is at the bottom; the newest is at the top.
Yes, they reveal where and why delivery stalls.