==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.0-beta2 PGSQL edition
- Deployed with iRedMail Easy or the downloadable installer? downloadable installer
- Linux/BSD distribution name and version: Ubuntu 18.04.03 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): NGINX
- Manage mail accounts with iRedAdmin-Pro? NO
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

nginx/error;log

2020/01/24 11:34:16 [notice] 6359#6359: signal process started
2020/01/24 18:13:42 [error] 6360#6360: *8728 open() "/var/www/html/api/1/http/upstreams" failed (2: No such file or directory), client: 172.105.93.108, server: _, request: "GET /api/1$
2020/01/24 19:22:03 [error] 6360#6360: *10112 open() "/var/www/html/+CSCOE+/logon.html" failed (2: No such file or directory), client: 169.197.108.22, server: _, request: "GET /+CSCOE$
2020/01/24 19:34:15 [notice] 21968#21968: signal process started
2020/01/24 20:57:15 [error] 21969#21969: *12035 connect() failed (111: Connection refused) while connecting to upstream, client: 52.125.140.0, server: _, request: "OPTIONS /Microsoft-$
2020/01/24 23:46:41 [error] 21969#21969: *15462 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 193.57.40.38, server: _, request:$
2020/01/25 00:40:51 [error] 21969#21969: *16560 open() "/var/www/html/solr/admin/info/system" failed (2: No such file or directory), client: 193.57.40.38, server: _, request: "GET /so$
2020/01/25 01:08:03 [error] 21969#21969: *17113 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 193.57.40.38, server: _, request:$
2020/01/25 03:58:30 [error] 21969#21969: *20571 open() "/var/www/html/+CSCOE+/logon.html" failed (2: No such file or directory), client: 169.197.108.22, server: _, request: "GET /+CSC$
2020/01/25 04:20:17 [crit] 21969#21969: *21017 SSL_do_handshake() failed (SSL: error:1420918C:SSL routines:tls_early_post_process_client_hello:version too low) while SSL handshaking, $
2020/01/25 12:52:03 [notice] 8256#8256: signal process started

It was working yesterday, but today, I am unable to access my mailboxes, and Roundcube tell me that he is unable to connect to the storage server.

I checked nginx error.log because dovecot.log told me too:

Jan 24 11:27:07 mail dovecot: master: Dovecot v2.2.33.2 (d6601f4ec) starting up for pop3, imap, sieve, lmtp (core dumps disabled)
Jan 24 11:27:07 mail dovecot: doveconf: Warning: SSLv2 not supported by OpenSSL. Please consider removing it from ssl_protocols.
Jan 24 11:27:07 mail dovecot: config: Warning: SSLv2 not supported by OpenSSL. Please consider removing it from ssl_protocols.
Jan 24 11:54:15 mail dovecot: master: Warning: SIGHUP received - reloading configuration
Jan 24 11:54:15 mail dovecot: master: Error: Error reading configuration:
Jan 25 12:52:20 mail dovecot: master: Warning: SIGHUP received - reloading configuration
Jan 25 12:52:20 mail dovecot: master: Error: Error reading configuration:
Jan 25 14:05:44 mail dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.
Jan 25 14:15:42 mail dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.
Jan 25 14:25:42 mail dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.
Jan 25 14:45:42 mail dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.
Jan 25 15:25:42 mail dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.