KBA-01690: EMail Loop


How do I stop a Mail Loop?


Sometimes, automated email gets frisky. When a bot receives an inbound email message, it is standard for that bot to reassure the original sender by returning a simple “got it” acknowledgement. Image a scenario where an email is routed to a Vendor’s RFQ email address. The vendor has a bot that responds “we got your request.” Spitfire’s ATC bot sees that email and sends a similar acknowledgement. The vendor then says “thanks” to the acknowledgement. And so on.

In addition to using both X-Auto-Response-Suppress and Auto-Submitted headers on automated outbound messages, ATC has some built in detection for such loops and will stop sending its acknowledgement.

ATC recognizes that an email message is an automation and should not be responded to if:

  • The messages X-Auto-Response-Suppress and/or Auto-Submitted headers are present
  • The message body contains
    • Your message was processed by our automated system
    • Do not reply
  • The subject contains
    • automated message
    • Auto(matic)-Reply
    • delivery delayed
    • do not reply
    • no longer valid
    • out of office
    • Mail delivery failed
    • (un or non) deliverable
    • failure notice
    • rejected
    • Ignored*
    • Processed*

To stop a loop:

On the ATC Server,

  1. Use the ATC Remote tool to PAUSE the ATC service.
  2. Use the POP Inbound Queue tool to review the inbox.
    1. Find the offending message and capture its headers for support.
    2. Delete the offending inbound message.
  3. Use the ATC Remote tool to RESTART the ATC service.

You can also use SERVICES.MSC to stop/restart the ATC service.

Additional Comments:

If you detect a loop, please forward the email as an attachment to Support!

The detection is driven by regular expression captures.

In an emergency, Support can help provide an override rule to detect your problem email.

Automated responses sent by ATC are RFC-3834 compliant.   As a final filter, ATC will pause sending acknowledgements to a specific email address if more than 9 have been sent without a 2 hour interval.

KBA-01690; Last updated: August 7, 2018 at 13:41 pm;