What are the differences between 5321.from and 5322.from in email headers?
Summary
What email marketers say7Marketer opinions
Email marketer from StackOverflow shares that 5321.MailFrom is part of the SMTP envelope (the technical information used for email transport), and 5322.From is part of the email's headers (what the user sees).
Email marketer from Mailgun shares that the 5321.MailFrom (Return-Path) is used for handling bounces, while the 5322.From is what the recipient sees in their email client. They can be different, but discrepancies can affect deliverability.
Email marketer from Postmark explains that the 5321.MailFrom is the Return-Path, which is where bounces go. The 5322.From is the friendly from address which is shown to the users.
Email marketer from Reddit explains that differences between the domains in 5321.MailFrom and 5322.From can trigger spam filters. Maintaining consistency and proper authentication (SPF, DKIM, DMARC) is key.
Email marketer from SparkPost explains that the 5321.MailFrom domain is checked during SPF authentication, while the 5322.From domain is often used for DKIM. Proper alignment between these domains is crucial for passing DMARC and improving deliverability.
Email marketer from SendGrid explains that SPF authenticates the 5321.MailFrom domain, confirming that the sender is authorized to send email on behalf of that domain. This helps prevent spoofing and improves deliverability.
Email marketer from Zoho explains that DKIM adds a digital signature to the 5322.From header, verifying the message's integrity. This ensures that the email hasn't been altered during transit and builds trust with the recipient's mail server.
What the experts say3Expert opinions
Expert from Email Geeks explains to understand email headers we need to know where subdomain.domain.com is located. The 5322.from can be the same at different ESPs but the 5321.from cannot. The d= value can be the same at different ESPs.
Expert from Word to the Wise explains that the relationship between 5321.MailFrom and 5322.From is vital for authentication protocols like SPF and DMARC. Discrepancies can lead to deliverability problems.
Expert from SpamResource explains that the 5321.MailFrom is the address used during the SMTP transaction and determines where bounces go, while the 5322.From is the address displayed in the recipient's email client.
What the documentation says3Technical articles
Documentation from RFC Editor explains that the 5322.From header is the 'From:' header field that email clients display to show the author(s) of the message. It's part of the message body and is for display purposes, not used by the SMTP server for routing.
Documentation from RFC Editor explains that the 5321.MailFrom (or Return-Path) is used during the SMTP transaction. It specifies where bounce messages should be sent. It's crucial for the actual delivery process and is used by servers to handle bounces.
Documentation from DMARC.org explains that DMARC uses SPF and DKIM to validate email sources. SPF checks the 5321.MailFrom domain, and DKIM often uses the 5322.From domain. DMARC alignment policies determine what happens to messages that fail these checks.