[Users] Unrecognized static network settings

[E.R.]

Hello everyone,
Claws mail fails to connect to the Internet when installed on a machine
which uses static IP, static route and static DNS addresses for its
network settings. I can't find how to configure Claws so that it adapts
to the those settings. I would appreciate your help to overcome this.
System configuration :
$ lsb_release --description
Description: Fedora release 22 (Twenty Two)
$ sudo systemctl status NetworkManager.service
● NetworkManager.service - Network Manager
   Loaded: loaded (...; enabled; vendor preset: enabled) Active: active (running)
$ claws-mail --version
Claws Mail version 3.13.1