Mail Up provides some powerful features in a very user friendly UI, in particular the journey builder is really easy to use especially for less technically minded people.
I used it as an admin when I worked for a retail company in 2014 and it was already one of the best solutions for small enterprises.
Quickly setup(same day) helpful salesperson and good support via FAQs.
I never received a warning and 5 days after the failed payment they deleted my account. It has been a year now and I'm still so angry.
Disappointed that the package didn't include SMS functionality and the contact import and configuration could be more streamlined and simplified.
The way they treat customers when something gets wrong.