UID Purge?

[Kevin]

Ok, two answers:

You read compressed dovecot.rawlogs using doveadm:

# doveadm dump -t imapzlib 20170328-183150-8404.in
2 namespace
3 COMPRESS DEFLATE
4 ID ("name" "Thunderbird" "version" "38.7.2")
5 list (subscribed) "" "INBOX.*" return (special-use)
6 list "" "INBOX"
7 select "INBOX"
8 getquotaroot "INBOX"
9 UID fetch 1:* (FLAGS)
10 IDLE
DONE
12 uid move 176 "INBOX.Archives.2017"
13 noop
14 getquotaroot "INBOX"
15 UID fetch 1:* (FLAGS)
16 IDLE
DONE
17 logout

and Thunderbird is making use of 'uid move'.

Kevin.