[Dovecot] TLS/SSL for Win8 & Outlook

Steffen Kaiser skdovecot at smail.inf.fh-brs.de
Thu Jun 26 11:40:20 UTC 2014

Hash: SHA1

On Thu, 26 Jun 2014, Adi Kriegisch wrote:
>>> I am struggling with the same issue for some time now: win8/outlook isn't
>>> able to connect to dovecot 2.2.9 (from Debian/backports); the error on the
>>> outlook side of things is 0x800CCC0E which is really helpful.
>> A listing of all of Window's error codes:
>> http://support.microsoft.com/kb/942495
> Yeah:
> 0x800CCC0E IXP_E_FAILED_TO_CONNECT  Cannot connect to server
> Pretty helpful error message after all... ;-)

Well, _did_ you've verified that the connection is started at all?

I mean: http://support.microsoft.com/kb/302339/EN-US

"If you are connected to the Internet through MSN, the Microsoft Network, 
and you attempt to send messages by using an account other than your MSN 
e-mail account, you may receive an error message that is similar to the 
following error message:

The connection to the server has failed. Account: '<account name>', 
Server: '<SMTP server name>', Protocol: SMTP, Port: 25, Secure (SSL): No, 
Socket Error: 10051, Error Number: 0x800CCC0E

This behavior can occur because MSN does not allow messages to be sent to 
another Simple Mail Transfer Protocol (SMTP) server while you are 
connected to their network."

- From that description I would first check if this error means the basic 
TCP connection. No SSL stuff or something.

> Seriously, Outlook (tried 2007 and 2013) use the MS Crypto API for
> establishing the SSL connection. This works with openssl s_server but does
> not with dovecot.

Actually, as Jerry already wrote, some other program may interfere, e.g. 
an antivirus program that stalls the connection as soon as the connection 
changes from text to binary after the STARTTLS command. That's what we 
had problems with.

Did you checked the connection with wireshark / tcpdump on the server 
side? What side sents the last packet, does one side terminates the 
connection, ... ?

- -- 
Steffen Kaiser
Version: GnuPG v1.4.11 (GNU/Linux)


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