Solves the error
```
[gonne@nodens:~]$ sudo nixos-install --flake 'git+https://gitea.mathebau.de/gonne/nixConfig?ref=updates#ghatanothoa'
building the flake in git+https://gitea.mathebau.de/gonne/nixConfig?ref=updates&rev=711f80c85e185ca9fe32a27492b5295f2ddc7a2f...
error: builder for '/nix/store/0iblfp7h8l97qflgcsv3kpnwvfzvr6bi-builder.pl.drv' failed with exit code 1;
last 1 log lines:
> error: executing '/nix/store/9nw8b61s8lfdn8fkabxhbz0s775gjhbr-bash-5.2p37/bin/bash': Permission denied
For full logs, run 'nix log /nix/store/0iblfp7h8l97qflgcsv3kpnwvfzvr6bi-builder.pl.drv'.
error: builder for '/nix/store/ssy2yzclqcsddsmqw60yd7vwc7843fw3-daniel-authorized_keys.drv' failed with exit code 1;
last 1 log lines:
> error: executing '/nix/store/9nw8b61s8lfdn8fkabxhbz0s775gjhbr-bash-5.2p37/bin/bash': Permission denied
For full logs, run 'nix log /nix/store/ssy2yzclqcsddsmqw60yd7vwc7843fw3-daniel-authorized_keys.drv'.
error: builder for '/nix/store/k4npfvmszrzr49yrm5k4hiz3p2c32jl7-etc-os-release.drv' failed with exit code 1;
last 1 log lines:
> error: executing '/nix/store/9nw8b61s8lfdn8fkabxhbz0s775gjhbr-bash-5.2p37/bin/bash': Permission denied
For full logs, run 'nix log /nix/store/k4npfvmszrzr49yrm5k4hiz3p2c32jl7-etc-os-release.drv'.
error: builder for '/nix/store/s72czr6ba3kf87hahwmg5lvjd9dwnjnz-mounts.sh.drv' failed with exit code 1;
last 1 log lines:
> error: executing '/nix/store/9nw8b61s8lfdn8fkabxhbz0s775gjhbr-bash-5.2p37/bin/bash': Permission denied
For full logs, run 'nix log /nix/store/s72czr6ba3kf87hahwmg5lvjd9dwnjnz-mounts.sh.drv'.
error: 1 dependencies of derivation '/nix/store/mm45kds7svlvi0w3fj33pfbcjbzcx2nl-nixos-system-ghatanothoa-25.05pre-git.drv' failed to build
[gonne@nodens:~]$
```
This directive is supposed to prevent mail delivery loops that would be caused by portforwarding to itself.
Behind this ip address, however, there is our general mail vm and not immediately the mailinglist setup.
