Recently the root certificate of our SSL provider IPS CA expired. This causes problems with all browsers and e-mail clients as the renewed signers certificate is not, obviously, in your browser's certificate store.

The CA bundle for IPS Seguridad SA is here:

http://certs.ipsca.com/store/IPS-IPSCABUNDLE.crt

To import the new IPS CA certificate into Firefox

Simply click on the link above and check the three boxes in the pop up.

To import the new IPS CA certificate into Thunderbird

Right Click [Control-Click on Mac] on the link in Firefox, choose Save Link As and save the file to Desktop.

In Thunderbird, go to the preferences/options menu.

On Linux, the preferences menu is in Edit -> Preferences. On Windows Tools -> Options.

Then Preferences -> Advanced -> Certificates -> View Certificates -> Authorities -> Import.

then select the file you downloaded to  the desktop.

Make sure you check the trust boxes as you did in Firefox.