Use Cases and Deployment Scope
On my specific side of things in marketing we started using SendGrid to relay our email communications from our CRM as we encountered deliverability issues. As part of our agreement we also conducted a multiple-week plan with their deliverability expert in order for us to learn the platform and its ins and outs, as well as general lesser-well-known deliverability best practices and things to consider, which were tremendously helpful.
Other Software Used
Adobe Marketo Engage, MxToolBox