I have tried to disconnect the plugin from my Mailchimp account and then to reconnect it, but I haven’t solved the problem.
I don’t know how to check if outgoing connections are being allowed or if my host has enabled the “fsockopen” php function.
However, I give you the details requested:
Wordpress version: 3.8
Plugin version: 1.4.1
Hosting provider: Altervista
Thank you!