July 10th, 2018

Email Delivery Status Tracking …. for successes, failures, and bounces of all kinds

LuxSci automatically tracks the delivery status for all email messages sent via SMTP, WebMail, and the LuxSci API. This report indicates whether or not the messages were successfully delivered to each recipient’s email servers, if they failed to be accepted there for some reason, or they are still queued at LuxSci. For many purposes, this automatic delivery status tracking is more than sufficient.

A standard automatic delivery tracking process has one limitation. For the case where an email message is successfully delivered to the recipient’s servers but then later it bounces back to the sender, the message will show as “delivered” (because it was) and there will be no indication of the subsequent bounce.

The optional “Automatic SMTP Bounce Processing” feature takes care of this situation.

How Automatic SMTP Bounce Processing Works

Once enabled, every message sent over SMTP is slightly modified so that bounces go back to a special system email address instead of to the message sender.

When bounces are received by this special address, they are analyzed and your delivery status report may be updated (if the message contains new and useful information). Two additional delivery states may be set by this process (e.g., in addition to standard delivery states like “Queued,” “Failed,” and “Delivered”):

  • Post-Delivery Hard Failure: This is set for messages that were successfully delivered to the recipient’s servers but which subsequently bounced back with an error indicating that the recipient address permanently can not be delivered to.
  • Soft Failure: This is set for messages that were successfully delivered to the recipient’s servers but which subsequently bounced back with an error indicating that the recipient address exists but you message was rejected (e.g., because their mailbox was full or they thought your message was Spam-like, etc.) or there was some other temporary issue which might not affect future messages to the recipient.

The delivery status details will also be updated with detailed information from the bounce message. “Hard Failures” should be removed from your mailing lists (a best practice for great deliverability). “Soft Failures” may be temporary issues. Note that the distinction between Soft and Hard failures can only be made by pattern matching the text of the bounce (they are not really different “kinds” of bounce).

Why is this feature not always enabled?

The side effect of capturing all of these post-delivery bounce messages is that the message sender address will no longer receive copies of these bounces. When enabled, senders will need to rely on one of the following mechanisms to be aware of failed email deliveries:

  • Login to LuxSci.com and look at the email delivery status reports.
  • Configure LuxSci to send periodic email digests listing recent email delivery failures.
  • Use the LuxSci API to download delivery status automatically.
  • Contact support to set up a dedicated bounce processing user on your dedicated email server.  You can then tap into the stream of bounce messages and create alerts, setup archival, and enable other custom processing of this email stream.

How do I turn on automatic SMTP Bounce Processing?

Automatic SMTP Bounce Processing can be enabled by LuxSci customers in one of two ways:

  1. By a domain administrator for all users in a domain. Go to the domain’s “Outbound Email Settings” and enable “Bounce Processing.”
  2. By any end user. Go to your “Settings – Outbound Email – Settings” page and enable “Bounce Processing.”

Either of these operations will enable automatic SMTP bounce processing for all outbound email messages sent by SMTP (not WebMail or API) by the affected users.

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