[Mailman-Users] How to check if E-mail from Mailman was opened by the subscriber ?

[Grant Taylor]

On 07/27/2017 11:04 AM, Robert Heller wrote:
> All you can know for sure is if the E-Mail was delivered and accepted by the 
> final MTA server.

You can't even be 100% sure of that.

You can use SMTP's DSN feature to request to be notified when a message 
is delivered.  However, chances are good that you will run into a server 
that will send back a DSN stating that the message has been relayed into 
a server / network that does not support DSNs.  Thus no assurance that 
the message even made it to the final MTA server.

> Whether that server tossed the message into
> the bit bucket, or if the end-user deleted it unread or just never got around
> to actually opening message is not something you can be totally sure of.

You can add a header to request an MDN, a.k.a. return receipt. 
Supposedly MDNs are supposed to tell you if a message was displayed. 
However that does not mean that the message was actually read.

Both DSNs and MDNs are fairly easy to thwart.  -  That being said, they 
are probably the best methods to go towards your goal.  It's just very 
likely that you will not actually achieve your goal.

There are other tricks, like images in HTML email, that can be used. 
They tend to be subject to various opinions about how spamy they are. 
Many of which are frowned upon for that reason.

*IF* you really do want to do something like this, use a graphic that is 
unique per user, make it actually show up (as more than 0x0 / 1x1 / etc) 
like a company logo does, and then track that way.



-- 
Grant. . . .
unix || die