Unable to log in to RoundCube: Connection to storage server failed

Symptoms

• Unable to log in to RoundCube:

  Connection to storage server failed.

• The Dovecot service is down with the error:

  # systemctl status dovecot.service
  dovecot.service – Dovecot IMAP/POP3 email server
  Active: failed (Result: exit-code)
  …
  doveconf: Fatal: Error in configuration file /etc/dovecot/conf.d/14-plesk-sni-mail.example.com.conf line 7: ssl_cert: Can’t open file /usr/local/psa/var/certificates/scfefbDGW: No such file or directory

Cause

Certificate misconfiguration.

Resolution

1. Log into Plesk

2. Go to Domains > example.com > Mail Settings

3. Set the value of SSL/TLS certificate for mail if it is not specified. 

4. Click the OK button. Also you may set mail certificate under Domains > example.com > SSL/TLS Certificates > Advanced Settings > Secure Mail.

5. Start the dovecot service:

   # service dovecot start