Can't connect to IMAPS using Outlook 2013

[Thomas Luft]

Hi there,

I am trying to set up an IMAPS connection with Outlook 2013 and am receiving
errors that Outlook can't create a secure connection tot he Kolab server. I
am using a SSL certificate from cacert.org which is installed at my computer
and is working in roundcube webmail.

mail.info shows:
Apr  1 22:53:24 kolab imaps[29669]: imaps TLS negotiation failed: xxx
.t-ipconnect.de [yy.zz.ccc.aaa]
Apr  1 22:53:24 kolab imaps[29669]: Fatal error: tls_start_servertls()
failed
Apr  1 22:53:24 kolab master[17496]: process type:SERVICE name:imaps
path:/usr/lib/cyrus-imapd/imapd age:32371.937s pid:29669 exited, status 75
Apr  1 22:53:24 kolab imaps[7704]: imaps TLS negotiation failed:
xxx.t-ipconnect.de [yy.zz.ccc.aaa]
Apr  1 22:53:24 kolab imaps[7704]: Fatal error: tls_start_servertls() failed
Apr  1 22:53:24 kolab master[17496]: process type:SERVICE name:imaps
path:/usr/lib/cyrus-imapd/imapd age:0.219s pid:7704 exited, status 75

It seems that TLS can't establish a connection with Outlook and I think this
might be something certificate related.

Does anyone have a clue where to start?

Kind regards

Thomas