WP/XAMPP local version – trouble with 'post by e-mail'

Hello
I have set up on a local network
– a virtual serveur through XAMPP
– a local version of WP

I have then set up the ‘post by email’ function (using gmail, then a classical POP3 without SSL > eg gmx.com)

However, when I go to /wp-mail.php, I get the below error message:

POP3 connect: Error [10061] [No connection could be made because the target machine actively refused it. ]

(and consequently, the post-by-email function is not working)

Thanks in advance for any suggestion !