Input Roundcube sending mail error

[Dave W]

OS ‪CentOS Linux 7.6.1810 (Core)‬
Product Plesk Onyx
Version 17.8.11 Update #65, last updated on Aug 26, 2019 04:38 AM

The server has an SSL assigned for Mail, *.our-domain.tld, the servers hostname is name.our-domain.tld

Sending mail via Roundcube returns an error:

[29-Aug-2019 15:11:47 UTC] ERROR: stream_socket_client(): unable to connect to ssl://localhost:465 (Unknown error) (0)
[29-Aug-2019 15:11:47 UTC] ERROR: Failed to connect socket: stream_socket_client(): unable to connect to ssl://localhost:465 (Unknown error) ()
[29-Aug-2019 15:11:47 +0000]: <58ijshl0> SMTP Error: Connection failed: Failed to connect socket: stream_socket_client(): unable to connect to ssl://localhost:465 (Unknown error) in /usr/share/psa-roundcube/program/lib/Roundcube/rcube.php on line 1667 (POST /?_task=mail&_unlock=loading1567091507176&_lang=en_US&_framed=1&_action=send)

Testing connections:

 openssl s_client -showcerts -connect localhost:465

CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 289 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : 0000
    Session-ID:
    Session-ID-ctx:
    Master-Key:
    Key-Arg   : None
    Krb5 Principal: None
    PSK identity: None
    PSK identity hint: None
    Start Time: 1567125025
    Timeout   : 300 (sec)
    Verify return code: 0 (ok)
---

Whereas:

openssl s_client -showcerts -connect name.our-domain.tld:465

returns the SSL certificate correctly.

The workaround we put in place was to edit
/usr/share/psa-roundcube/config/config.inc.php

and add:

$config['smtp_server'] = 'ssl://name.our-domain.tld';

this overrides the

$config['smtp_server'] = 'ssl://localhost';

in /usr/share/psa-roundcube/config/defaults.inc.php

Mail in roundcude sends correctly now.