Great question. Here is what I sent them today on an evaluation form. I hope somebody at mail.com reads it.
Suggestion 1: I really need mail.com to prevent your customers from sending spam. Put another way, you need to keep yourself off of the spam blacklists, otherwise you are useless to us. Comcast blocked all mail from 74.208.4.200 for 24 hours and I lost email. Please understand, it doesn't matter whether the customer knows he has a virus and is sending spam or not. YOU SHOULD KNOW IF SPAM IS BEING SENT THROUGH YOUR SERVERS. Maybe you need to work on this. Remember, I am forwarding my mail to my ISP. If they receive too many complaints that your IP addresses are sending spam, THEY WILL SHUT DOWN ALL MY INCOMING EMAIL.
Suggestion 2: I am rating your response time inadequate because your contact form is completely useless. Why? Because the customer cannot quickly send you a bounce notice. I have complained about this in the past but you do not seem to care. You need to have button so a premium user can browse to a file and attach it. Or else you need to have an email address where a premium user can quickly forward a bounce notice - one step, not two or three or four. Don't make your premium customers waste time sending useless forms and then waiting around for someone to email them back so they can send a bounce notice. When a customer's email is being blocked, they don't want to play games, when every minute and hour that passes means no email. They want to send you the bounce notice, one step. Why don't you guys understand this from the user's point of view?
Based on the above, the experience with the customer service agent is not relevant. The agents are not the problem.