[Dovecot] 1.2.11 logging with TLS

[Sven]

Hi guys,

i am new to dovecot but till now everything works as desired.
i am setting up a SSL only environment. when i configure

ssl = required
verbose_ssl = yes
auth_verbose = yes
auth_debug = yes

i get no warning that ssl/tls is not activated in the client. or 
STARTTLS not sent. the only thing that appears is

Aborted login (no auth attempts): rip=192.168.1.21, lip=192.168.1.20

when activating tls in thunderbird everything works fine.
is there a way getting more verbose failures on this?
do i miss something?

Thanks in advance
Sven