ConvertKit

This is by far the best platform for organizing how you want your email series to be sent out as well as for tagging subscribers according to how they respond to your emails (like if they click on a button in your email to learn more, sign up for something, buy something, etc.).

If you know what you're doing, this is an intuitive platform that allows you to keep track of what your subscribers are doing and then target them with the appropriate marketing.

I feel like ConvertKit isn't beginner friendly because when you first sign onto there the interface is too overwhelming. The positive is that they give you a lot of options as to what you can do in email marketing and then the negative is that they give you too much options so then, like I said, it just looks overwhelming as a platform to work with.

They do have tutorials though as well as a trial so you can get to know the platform before you jump into the monthly fee that starts at $29.

It's easy to write emails and develop an email funnel.

the implimentation is dire, it's like a beta release all the time.
the forms aren't as responsive as they so claim, things look good on their page and then on preview, but when published, you really have to tinker with them to make them work.
Their worpdress plugin was prompting 'malware' warnings on my site with Avast, the first time I had to contact their help desk, and they were more concerned about removing me from their daily tasks lists than dealing with the problem.

this eventually cleared up, I assume it may have been in Avast's hands, but this problem lasted two weeks in convertkits hands.

I then had a list of 5 questions, I recieved a response for one of them by [SENSITIVE CONTENT HIDDEN] who I then didn;t reply in a timely manner for (although he contacted me 3 days after my problems were raised!)
He then got pushy in the emails for me to deal with the problem immediate - which I couldn't do!! I was available to add things to my website 3 days before his response and had other work commitments to deal with, having just now got back to the website, 5 days after my initial problems, he decided to close the ticket to and I quote 'remove them off his daily tasks lists'
I've now raised these exact same questions again to convertkit to seek help, hopefully I won't get an automated response and have to wait another 3 days for a reply to when im busy and told they'll close the ticket again to make themselves look good.

Their customer service is diabolical and their software is sub par.