At the time of this article in October 2015, the HTML swiftmailer module version for Drupal 8 was not released. Thus the below solution is not relevant anymore but may help for configuration or setup. We also have a new post about installation of swiftmailer
Here is a possible solution for sending HTML mails with Drupal 8 specifically when creating custom modules.
The solution below uses Swiftmailer library.
This version needs some corrections if it is used with a recent Drupal 8 release. In this case, these are the lines changed:
Configuring Drupal with a remote database is possible and in some cases recommended.
Our Drupal 8 EK management tools application is a particularly good case where this setup is very helpful. EK manages Drupal system configuration database and content database separately. In other words, the installed database from Drupal 8 and the database where all EK custom modules save their data are different.
This configuration brings few benefits: