Persistence paid off. I found another example where they mentioned the old method being deprecated. So ConnectAPI was the answer. Thanks @cropredy
You will not get the announcement record because the- announcement has a relation to feed item which is required field on the announcement object. So, once feed item gets inserted then only announcement records will get inserted.
Understand the whole process with this: Creating a group announcement is a three-step process.
Use the FeedItem object to create ...
Yes, You can pre-defined the from address on an email action. Open your action, click new on pre-defined field values section.
Select from in the field to be pre-defined and then select the email address you want to default for your email action in specific value dropdown and save it.
Read more here:- Set Predefined Field Values for Quick Action Fields