Proxy problem: "[COMPRESSIONACTIVE] TLS compression already enabled"

[Timo Sirainen]

On 14 Oct 2014, at 15:24, Ralf Hildebrandt <r at sys4.de> wrote:

> We're proxying using 2.2.14~rc1 (on our IMAP Proxy) to two dovecot
> backend servers running dovecot-2.2.13-r1
> 
> When we're using Thundebird to connect to the dovecot proxy, we're
> getting the message "The mail server for account ACCOUNTNAME
> responded: [COMPRESSIONACTIVE] TLS compression already enabled"
> 
> But why?

Is the connection from proxy to backend using SSL? Did this work in earlier Dovecot version?