Pascal Volk suggested this, and it was pretty quick to implement for Dovecot v2.0. Ideas welcome how to improve it, or if it's already perfect :)
The first line is written to stderr, so |sort can be used:
doveadm who|sort
username # (ips) (pids) timo 1 (127.0.0.1) (2457) tss 2 (127.0.0.1) (617 1345) tss2 2 (127.0.0.2 127.0.0.1) (2392 2799)
doveadm who|sort -k2 -nr
username # (ips) (pids) tss2 2 (127.0.0.2 127.0.0.1) (2392 2799) tss 2 (127.0.0.1) (617 1345) timo 1 (127.0.0.1) (2457)
You can filter connections:
doveadm who 127.0.0.2
username # (ips) (pids) tss2 2 (127.0.0.2 127.0.0.1) (2392 2799)
doveadm who 127.0.0.0/24
username # (ips) (pids) tss2 2 (127.0.0.2 127.0.0.1) (2392 2799) timo 1 (127.0.0.1) (2457) tss 2 (127.0.0.1) (617 1345)
doveadm who tss
username # (ips) (pids) tss2 2 (127.0.0.2 127.0.0.1) (2392 2799) tss 2 (127.0.0.1) (617 1345)
doveadm who tss 127.0.0.1
username # (ips) (pids) tss2 2 (127.0.0.2 127.0.0.1) (2392 2799) tss 2 (127.0.0.1) (617 1345)