We currently have a private cloud installation of Drupal 7 (with a custom template and some custom modules), and looking to migrate to Drupal 8. We understand this will require a lot of work as it's not a straight forward migration path.Are there any...

This is an onprem installation. Emails (all system / rule based emails) work fine unless a user checks ' Plaintext email only' option in their user profile. When they have it checked, the email fails with a message to contact the system administrator...