tlsv1 alert unknown ca: SSL alert number 48

[Gedalya]

On 06/18/2016 02:27 AM, Maurizio Dall'Acqua wrote:
> The version of Roundcube I am using is 0.9.5+dfsg1-4.1

If you want to get a newer version using Debian packages, perhaps try to add the following line to /etc/apt/sources.list :

deb http://httpredir.debian.org/debian jessie-backports main

Then run:

apt-get --dry-run -tjessie-backports install roundcube

and take a close look at what's being pulled from where, make sure it all makes sense to you.

Then run it again, for real:

apt-get -tjessie-backports install roundcube

This should get you roundcube 1.1.5+dfsg.1-1~bpo8+1 from Debian's repository, while pulling necessary dependencies from your native raspbian.