Comment 31 for bug 1713803

postfix takes a copy of resolv.conf for its own use, in its own queue directory. This is already well integrated by way of either resolvconf triggering the copy on changes (using update-libc.d) or by if-up / if-down. This will need work to "improve" the integration story; however postfix should still work well in its current state with systemd given that the effective nameserver should remain just the local systemd-resolved.