That indeed contains the offending "search .". Since the file is managed by systemd-resolved the question becomes where exactly that comes from.
To ensure this is the case check /run/systemd/resolve/stub-resolv.conf which is the file that pushes info from systemd-resolved into resolv.conf. There it should also have the "search ." entry. Furthermore you can check which connection of yours is proving that. $ systemd-resolve --status In my example /run/systemd/resolve/stub-resolv.con holds "search fritz.box buildd" of which I can see in --status that "buildd" is from a VPN connection I have and "fritz.box" is from my local router (seen on lan and wlan interface). That could be the first step to get a feeling "where it is coming from" It could be: - from your dhcp server that pushed this search domain - from your local dhcp config that has an entry to append this search domain - "search" statement via local config in /etc/netplan/* - as config of "Domains=" in /etc/systemd/resolved.conf - somewhere buried int he network-manager gui (If you are on a desktop) - ... (I might have missed one) But the next step IMHO is to find where that config really comes from to adapt/fix it there. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1906970 Title: dpkg hook hostname error To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/postfix/+bug/1906970/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs