client unix_listen .dovecot-client
c = ./dovecot-auth-cli .dovecot auth username password
client -> VERSION	1	1
client -> SPID	12345
client -> CUID	12345
client -> COOKIE	lovelycookie
client -> MECH	PLAIN
client -> MECH	LOGIN
client -> DONE
client <- VERSION	1	1
client <~ CPID	
client <- AUTH	1	PLAIN	service=smtp	secured	no-penalty	nologin	resp=dXNlcm5hbWUAdXNlcm5hbWUAcGFzc3dvcmQ=
client -> OK	1
c <- yes
c wait 0