What is a Bounce Back?
A bounce back (or bounced e-mail) is an e-mail message that could not be delivered because of a problem with the recipient's e-mail address. netFORUM Pro tracks hard bounce backs, but does not track soft bounce backs.
A "hard" bounce is a message that is returned to the sender immediately because the e-mail address is invalid.
A "soft" bounce is an e-mail message that does not reach its destination because the recipient's e-mail address is temporarily unavailable (for example, the recipient's Inbox is full, or the recipient's e-mail server is down for an hour). The sender does not receive immediate notification of a "soft" bounce because the message remains in the queue and the recipient's e-mail server tries to deliver it again. The number of delivery attempts depends on the recipient's mail server settings.
Hard bounce back errors can now update one of the following flags through enhancements to Email Blaster, the messaging engine of netFORUM:
- Invalid Email Flag
- Do Not Contact By Email Flag
Email Blaster will no longer send to customers who have their Invalid Email Flag or Do Not Contact By Email flag set.
Note: If an email address is changed or updated, the email will reset the Invalid Email flag and also clear the Invalid Email Reason. The email blaster also logs the count of Invalid Email Flags and Do Not Contact By Email flag that were set at the time of sending.
Enhancements have also been made to hard bounce back tracking. Tracked bounce backs include:
- the server rejected one or more recipient addresses
- unable to relay for
- mailbox unavailable
- mailbox not found
- invalid mailbox
- user unknown
- unknown user
- not our customer
Custom headers have been added to each email sent by Email Blaster. Parameters will be used by the Email Listener app for identification of emails being sent. These parameters are:
- Return Path: Copies of all bounced emails are requested to return to a specified mailbox of Abila for further processing.
- X-AV-ENT: The entity key of the client sending the email
- X-AV-MSJ: The messaging job through which the email was sent
- X-AV-MSM: The log record of the messaging job that was sent
- X-AV-CST: The customer key of the email recipient
- X-AV-EML: The actual email address of the recipient
Finally, netForum has built-in functionality that attempts to track soft bounces as well but has limited ability regarding those bounces. This is because soft bounces are directly dependant upon on how the recipient email servers respond to them. netForum’s messaging engine requests from the recipient servers that soft bounces are forwarded to a specific mailbox at Abila (by adding a “Return-Path” to the header of outbound emails as detailed above), so that the netForum bounce tracking engine can process these soft bounces and mark the appropriate flags in the database, but not all recipient servers follow these instructions. Further, recording bouncebacks on messaging jobs is an arduous task. With many different server environments, there are many configurations with no set standards between servers and how bounce-backs are gathered or treated. Abila has improved the bounce back code to 'cast a wider net' to ensure optimal capture of bouncebacks however, the continual updates that we have added to this functionality will still not collect 100% of emails that are bounced back. Here is why: Abila can only control the 'sending' of the email message. Your customer's environment (the recipient server) generates the bounced emails. Therefore, controlling the bounced email 'rules' for their environment cannot be controlled by Abila. To explain further, a recipient server can choose to not bounce back or to bounce to the actual sender and not to the "return-path" which points to our Abila Exchange server. These are just two of the scenarios that recipients can choose when managing how to handle bounces.