A new and updated documentation is now available on getting started with transactional messaging. And, the transactional messaging limitations document has also been updated and moved under the transactional messaging section.
Please read through the below documentation links for more details:
In case you have any questions, please feel free to post them below or reach out through the community Q and A section. In case you have any ideas and/or suggestions regarding the Campaign Standard product, then kindly submit them here.