I have been using this for about 4 plus years now and love it.

I have used this on InMotion Hosting, Linode, Digital Ocean and it works great. Some hosting providers do block this due to its abilities but if your provider doesn’t block it this is one of the best plugins out there and I highly recommend using SendGrid. I am always informed of an issue and never have I been black listed. I do run a legit business so maybe that is the reason.

With SendGrid I have a 99% Reputation, better than I do with any other system out there.

To make it work right you must know very little about APIs and how they work, not difficult but you might need to know how to use them.