Support Postmark "Tag" and "TrackOpens"

[jaketoolson]

PostmarkApp's API has additional methods "Tag" and "TrackOpens" http://developer.postmarkapp.com/developer-api-email.html#send-email

It would be nice to add these optional methods.

[ivank]

A nice suggestion :) 10x will try to implement at some point.
The sad part is that from a quick poking around Swiftmailer I couldn't find a way to make this a "per message" assignment, it should probably have to be set directly to the transport...

[jaketoolson]

@ivank -- I came to the same conclusion. I was hoping to just add a method to message but it would almost require a custom extension of Swift_Message or a trait. The only other thought I had was listening to the swift events and doing it this way.

[ivank]

Swift employs special "X-Swift-...." headers to pass custom message data around internally.

https://github.com/webasyst/webasyst-framework/blob/master/wa-system/vendors/swift/classes/Swift/Plugins/RedirectingPlugin.php

We might be able to use some mechanism like this.

E.g.

// By doing this directly
$message->getHeaders()->addTextHeader('X-Swift-Postmark-Track', true);

// Or maybe by adding a static method to do that for us
Swift_PostmarkTransport::setTrack($message);