How to detect automatically generated emails - arp242.net

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1. Many delivery failure messages don’t really indicate that they’re failures. Some ways to check this: “From contains mailer-daemon or Mail Delivery Subsystem” Specific mail library footprints

   In Bounce types and SMTP codes

2. HTML only “If an email only has a HTML part and no no text part, it’s a good indication this is an autogenerated email or newsletter.” Delivery failures

   In Cold email formatting

3. “At best, you will get a useless delivery failure. At worst, you will get an infinite email loop and a world of chaos.” Turns out that reliably detecting automatically generated emails is not always easy. Here are my observations based on writing a detector for this and scanning about 100,000 emails with it (extensive personal archive and a company archive); it’s been working well for several years (I originally wrote this in 2015).

   In Automated reply filtering

4. Turns out that reliably detecting automatically generated emails is not always easy. Here are my observations based on writing a detector for this and scanning about 100,000 emails with it (extensive personal archive and a company archive); it’s been working well for several years (I originally wrote this in 2015). “Defined in RFC 3834.” This is the ‘official’ standard to indicate your message is an autoreply. You should not send a reply if Auto-Submitted is present and has a value other than no.

   In Automated reply filtering

5. Defined in RFC 3834. “This is the ‘official’ standard to indicate your message is an autoreply.” Defined by Microsoft

   In Automated reply filtering

6. This is the ‘official’ standard to indicate your message is an autoreply. You should not send a reply if Auto-Submitted is present and has a value other than no. “Defined by Microsoft” This header is used by Microsoft Exchange, Outlook, and perhaps some other products. Many newsletters and such also set this. You should not send a reply if X-Auto-Response-Suppress contains DR (“Suppress delivery reports”), AutoReply (“Suppress autoreply messages other than OOF notifications”), or All.

   In Automated reply filtering

7. Defined by Microsoft “This header is used by Microsoft Exchange, Outlook, and perhaps some other products.” List-Id and List-Unsubscribe headers

   In Automated reply filtering

8. Defined by Microsoft “Many newsletters and such also set this.” List-Id and List-Unsubscribe headers

   In Automated reply filtering

9. When you send out an autoreply from an email system you want to take care to not send replies to automatically generated emails. At best, you will get a useless delivery failure. At worst, you will get an infinite email loop and a world of chaos. “reliably detecting automatically generated emails is not always easy.” Defined in RFC 3834.

   In Automated reply filtering

10. “not send replies to automatically generated emails.” Turns out that reliably detecting automatically generated emails is not always easy. Here are my observations based on writing a detector for this and scanning about 100,000 emails with it (extensive personal archive and a company archive); it’s been working well for several years (I originally wrote this in 2015).

    In Automated reply filtering

11. Defined in RFC 3834. “You should not send a reply if Auto-Submitted is present and has a value other than no.” Defined by Microsoft

    In Automated reply filtering

12. Defined by Microsoft “You should not send a reply if X-Auto-Response-Suppress contains DR (“Suppress delivery reports”), AutoReply (“Suppress autoreply messages other than OOF notifications”), or All.” List-Id and List-Unsubscribe headers

    In Automated reply filtering

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