dovecot - Jan 2017 - IMAP proxy for Exchange - encrypted backend Communication?

Hello,

I try to setup a IMAP proxy for my old Exchange server.
Running Dovecot v2.x on Centos 7.

So far I follow http://wiki2.dovecot.org/HowTo/ImapcProxy and it seem
to work. The only but major  thing is with this setup - the
communication between proxy and backend is not encrypted. :(

To fix this, I changed the config and add:
imapc_ssl=imaps
imapc_port=993

but it doesnt work, because of verify failure of the self signed
backend certificate:

Jan  5 21:48:55 imap dovecot: imap(user1): Error:
imapc(192.168.1.1:993): Couldn't initialize SSL context: Can't verify
remote server certs without trusted CAs (ssl_client_ca_* settings)
Jan  5 21:48:55 imap dovecot: imap(user1): Error:
imapc(192.168.1.1:993): No SSL context
Jan  5 21:48:55 imap dovecot: imap(user1): Error: imapc: Command
failed: Disconnected from server
Jan  5 21:48:55 imap dovecot: imap(user1): Error: user tkoenig:
Initialization failed: Initializing mail storage from mail_location
setting failed: Mailbox list driver imapc: Failed to access imapc
backend
Jan  5 21:48:55 imap dovecot: imap(user1): Error: Invalid user
settings. Refer to server log for more information.

I didnt found anything in the documentation which tells dovcot not
verify the backend certificate.

Is there a know way to get it runing?

Many thanks for any hint!

regrds,
Tom

> On 5 Jan 2017, at 22.56, tom <posturne at gmail.com> wrote:
> 
> Hello,
> 
> I try to setup a IMAP proxy for my old Exchange server.
> Running Dovecot v2.x on Centos 7.
> 
> So far I follow http://wiki2.dovecot.org/HowTo/ImapcProxy and it seem
> to work. The only but major  thing is with this setup - the
> communication between proxy and backend is not encrypted. :(
> 
> To fix this, I changed the config and add:
> imapc_ssl=imaps
> imapc_port=993
> 
> but it doesnt work, because of verify failure of the self signed
> backend certificate:
you need to set:

imapc_ssl_verify = no

Regards,
Sami

thx, I'll try it. Currently I use stunnel as a quick and dirty work around. 

Tom

Am 6. Januar 2017 18:04:57 MEZ schrieb Sami Ketola <sami.ketola at
dovecot.fi>:
>
>> On 5 Jan 2017, at 22.56, tom <posturne at gmail.com> wrote:
>> 
>> Hello,
>> 
>> I try to setup a IMAP proxy for my old Exchange server.
>> Running Dovecot v2.x on Centos 7.
>> 
>> So far I follow http://wiki2.dovecot.org/HowTo/ImapcProxy and it seem
>> to work. The only but major  thing is with this setup - the
>> communication between proxy and backend is not encrypted. :(
>> 
>> To fix this, I changed the config and add:
>> imapc_ssl=imaps
>> imapc_port=993
>> 
>> but it doesnt work, because of verify failure of the self signed
>> backend certificate:
>
>you need to set:
>
>imapc_ssl_verify = no
>
>Regards,
>Sami