There are some possibilities to extend luxletter.
All HTML-Templates (and Partials and Layouts) can be overwritten by your extension in the way how templates can
be overruled in TYPO3. This fits the own content element Teaser and the rendering for the FluidStyledMailContent
elements as well as the templates for the backend modules of luxletter and the NewsletterContainer.html.
If you want to manipulate the PHP, there are a lot of signals added to the extension itself. Just search for
signalDispatch. You will find a lot of methods where you can stop mail sending, manipulate values, etc...
No, luxletter works without the extension lux but you can also install the free extension lux. After that, you can also use the Receiver action in the backend module to see some usefull information about the receiver activities.
Lux is a free marketing automation tool as a TYPO3 extension and a perfect fit for luxletter.
Of course, you can. Look at Installation to see a configuration example.
Luxletter uses FluidStyledMailContent to render some content elements in an oldschool HTML-style for a wide bunch of mail clientes.
No, not at the moment. We focused on fe_users.
At the moment there is no bounce mail handling integrated.
Look at the sys log to see which problem caused this issue. E.g. if fe_users.crdate is empty, etc...