Adrien
understood, so you mean Google reviews.
Not much of interested, beside some shared-hosting down, auto-renew, dislike portal, etc. all of them valid, but i see those complaints on pretty much every provider that has too many clients.
For security concern, you should read their FAQ section, i don't work for them, but since the mail.baby website is just a landing page, on wich, if you want to contract the service you will be a client of the real company, Interserver, you should read about privacy policy and security on the company website, interserver.
I can't comment on Uptime, speed or anything, i don't use interserver other services, only mail.