If you are not using email as a principal method of contacting your Users - you should! And you must ensure that you maintain tight control of this valuable / sensitive data. And for those people who already use the method, you'll know how unnecessarily difficult these services can be to manage reliably!
The thing about campaigns is that they consume a lot of management time. Many people will use "external" providers as the email service providers, such as Mail Chimp. To do so, you have to get your contacts out of your own systems and into the Mail Chimp service, import newly obtained Contacts lists, set up un-subscription details, set up links back to the website, configure metrics, bounce management, follow on emails ... and how are those follow on emails going to be handled - separately or part of a bigger "campaign"?
And can the campaign be controlled - set emails to go in specific order and with specific time gaps. And can this be achieved with the highest confidence that email reputation is not adversely affected? And can you use email responses to manage user account validity?
Have a look at XPOR Campaigns, built into your XPOR service and working with live contact data. And perfect for the forthcoming GDPR concerns! All under one bonnet - exactly where you need it.
Better than that, it's easy to configure and manage, including the feedback management of user accounts, with maximum bounce counts.