Understanding email bounces after delivery confirmation
Overview
When an email sent from Ortto and it is successfully received by the recipient's server, a Received email activity will be logged. This means that the receiving server accepted the email. However, it's possible that the email can bounce even after it has been accepted.
Why do emails bounce after they've been received?
This type of behavior occurs when a mailbox service initially accepts all messages for a hosted domain before checking other acceptance parameters, like mailbox status, mailbox storage, content requirements, etc. These types of bounces are called asynchronous bounces.
TIP: This generally occurs most often with organizational mailboxes like business domains.
Learn more about email non-delivery and complaints.
How to prevent asynchronous bounces
Following best practices such as keeping a clean list and ensuring recipients have explicitly opted in to receive marketing communication is the best way to avoid this behavior.
To make sure your efforts align with deliverability best practices, review our deliverability resources.
Can other odd email activities occur even after bouncing?
It is less common, but other email activities like opens and clicks can occur after the receiving server rejecting/bouncing the email.
Security servers on the receiving end are known to check images and some links from time to time. When doing so, they check via activities that appear similar to organic human opens/clicks so that our system is unable to confidently identify one from the other, which is intentional on their end. They do this for a myriad of security reasons that are important to the safety of their system and users.
While there is no way to outright stop this from occurring, there are some best practices to follow to help lower the likelihood that they'll occur, which are outlined here.