I have had this imaptest[1] stall. I compared this command with what you
have on the website and I was a bit surprised that what is on the
website is working. What I have noticed is that if you remove this msgs
argument, the imaptest stalls. I am not sure if this is according to
design, but one might expect that specifying a secs, makes specifying
msgs redundant?
[1]
imaptest - append=100,0 logout=0 host=xx.local port=143 user=xxx
pass=xxx seed=100 secs=240 clients=1 mbox=64kb.mbox box=inbox/test.
[2]
https://doc.dovecot.org/admin_manual/sample_tests/
Using: dovecot-imaptest-2.3.10-2.x86_64
