How can a bounced email show as opened or clicked?

Now and again you might come across a bounced email (i.e. an email that was returned by the recipient's email server without being delivered) but it is marked in MailMerge365 as opened. 

Here are some causes for this:

• First note that: 
  • Click tracking works by changing your original link to one that first redirects to MailMerge365 systems and then to the original user (this is transparent for the user in most cases). 
  • Open tracking works via an invisible embedded tracking image that is requested from our servers when the email is opened. 
  • See here for details on both.
• Some organisations will use security or caching services that will look at all incoming email (even before an attempt to deliver it is made) and (1) call all the links and (2) retrieve all the images, therefore triggering the "ClickeD" or "Opened" in MailMerge365. They do this in order to see if there is anything malicious in the email.
  • MailMerge365 can't differentiate between a real user and these security systems because that would defeat the purpose of a security system (a bad actor would for example just show a harmless response when it detects that the security software is request it, but the harmful response when it is the real user).
• Then the recipient's organisation:
  • may try to deliver the email and find out that the mailbox does not exist, in turn causing an NDR (non delivery response, often referred to as a bounce).
  • may determine the content to be spam or other unwanted material and reject delivery, again causing an NDR (this time the NDR will usually contain some information about the exact rejection)

This can cause an email to be both marked as clicked or opened and bounced at the same time.