imapsync from cyrus to exchange

Hi folks,

I use a modified imapsync 1.223 (modified: ignore Mails on source
with /deleted flag) and I can successfully log on to Cyrus using an
admin account with the --authuser feature. However, this works only
with --ssl which is secure but slows down the transfer a lot. Is there
a way to configure Cyrus to allow me PLAIN login without ssl? When I
try to log on without ssl and without authuser feature, Cyrus
complains about not being capable of doing it but it does it anyhow:

This is part of the output with --user1 user --password1 password --
authmech1 PLAIN (and no --ssl1). You see an error and then a success!?

From imap server [imap.lb.devk.de] port [143] user [lbmail1]
To imap server [10.28.73.170] port [143] user [domain/admin/user]
Banner : * OK sun1rd58 Cyrus IMAP4 v2.1.15 server ready
Host imap.lb.company.com says it has NO CAPABILITY for AUTHENTICATE
PLAIN
Frequently PLAIN is only supported with SSL, try --ssl1 or --ssl2
option
Error login : [imap.lb.company.com] with user [user] auth [PLAIN]:
Timeout after 4 seconds during read from server
Trying LOGIN Auth mechanism on [imap.lb.company.com] with user
[lbmail1]
Success login on [imap.lb.company.com] with user [user] auth [PLAIN]

Is there a way to
- enable PLAIN without ssl? or
- fasten up the transfer using ssl?
also I have some mail saying:

Warning : no header used or found
no header so taking everything
F msg 162:1B2M2Y8AsgTpgAmY7PhCfg:6398
Head NUM:0
´
when I use --ssl1 and that does not happen without --ssl1. It costs a
lot of time :-(

It would be really great If someone has a solution for that :-)