We have been using the Journey Builder in following way:
First we create a Campaing on Sales Cloud, then we create a simple journey in Journey Builder (Campaign entry source and Email send activity) and after activating we were doing a bulk upload to the Sales force Campaign.
This usually works fine, but recently we noticed not all contacts in Campaign are entering the Journey, for example we add 4000 contacts to Campaign but only 2800 get entered into the Journey. We have no-re-entry setup in the Journey, so we usually delete everyone from Campain and readd them. Sometimes everyone else gets added and sometimes just a part of contacts get added to journey.
My question is following:
What is the best method of sending such newsletters to few thousand people, where we only send one email, to make sure it works fine and everyone gets into the journey without having to reupload everyone to the campaing?