systemd restart on failed and notify

example.service

[Unit]
After=postgresql.service

[Service]
Type=simple
ExecStartPre=/bin/bash -c '(journalctl -n 5 --user-unit=%n | grep "Failed with result") && \
                           (journalctl -n 50 --user-unit=%n | mailx -s "[systemd] %n failed" user@domain.ua) || \
                           true'
ExecStart=/usr/bin/python3 /home/user/daemon.py
Environment=PYTHONUNBUFFERED=1
Restart=on-failure
RestartSec=10s

[Install]
WantedBy=default.target