Problem with SHA2/Geotrust and dovecot 2.0.9

[Il Neofita]

Hi
I have renew my geotrust certificate using sha2, and I have problem with
Dovecot 2.0.9 and redhat 6.7.
The same certificate is working in Apache.

The error is

dovecot: imap-login: Fatal: Can't load ssl_cert: There is no valid PEM
certificate.

and the configuration file is

ssl_cert=</etc/pki/dovecot/certs/2015/new.2015.pem
ssl_key =</etc/pki/dovecot/private/new.2015.key
ssl_ca = </etc/pki/dovecot/certs/2015/new-intermediate.crt

What I should do?