sudo -i
apt-get purge -y python3-pip
wget https://bootstrap.pypa.io/get-pip.py
python3 ./get-pip.py
apt-get install python3-pip
Applying this commands fixed it
After successful run of the command sudo mailinabox
Still got the Somthing went wrong message.
Than I ran the upgrade command
curl -s https://mailinabox.email/setup.sh | sudo bash
To install the latest version.
And it worked. Now receiving mail and the system check works.