Postfix SASL auth - client alway sent e-mail even password change until I run again client app

[Tomasz Kopczyński]

Hi.
I configured client auth for sending  emails. Everythings work fine but 
when I change password for user I still can send email from outlook or 
thunderbird with old password until I don't close mail client. If I run 
again thunderbird then server ask me for new password. Is there any 
command configuration to check password for every e-mail send or session 
idle?

I have the same problem with imap (dovecot). Even if I change password 
for user I can read email in thunderbird until I close it.

Regards,
Tomasz