RainLoop version, browser, OS:
1.10.4.183
Expected behavior and actual behavior:
Cannot connect to mailserver IMAP and SMTP using SSL/TLS with standard ports 993 and 465 respectively.
Steps to reproduce the problem:
Domain - Administration - klick "test"
Logs or screenshots:
`[14:26:54.640][f67cd494] SMTP[NOTE]: Start connection to "ssl://mehl.biszumbitterenen.de:465"
[14:26:54.699][f67cd494] SMTP[NOTE]: Connected (unsuccess)
[14:26:54.699][f67cd494] SMTP[NOTICE]: Socket: [2] stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed
[14:26:54.699][f67cd494] SMTP[NOTICE]: exception 'MailSo\Net\Exceptions\SocketCanNotConnectToHostException' with message 'Can't connect to host "ssl://mehl.biszumbitterenen.de:465"' in /var/www/mail/rainloop/rainloop/v/1.10.4.183/app/libraries/MailSo/Net/NetClient.php:292
Stack trace:
#0 /var/www/mail/rainloop/rainloop/v/1.10.4.183/app/libraries/MailSo/Smtp/SmtpClient.php(168): MailSo\Net\NetClient->Connect('mehl.biszumbitt...', 465, 1, true, false)
#1 /var/www/mail/rainloop/rainloop/v/1.10.4.183/app/libraries/RainLoop/Actions.php(4181): MailSo\Smtp\SmtpClient->Connect('mehl.biszumbitt...', 465, 'mehl.biszumbitt...', 1, true, false)
#2 [internal function]: RainLoop\Actions->DoAdminDomainTest()
#3 /var/www/mail/rainloop/rainloop/v/1.10.4.183/app/libraries/RainLoop/ServiceActions.php(172): call_user_func(Array)
`

There's no issue with other mail clients, e.g. Thunderbird using the same connection protocol / port.
Connecting with Roundcube is working, too.
Where is RainLoop looking for the SSL certificate?
In a specific directory of the webserver?
I have configured a reverse proxy (HAproxy) serving all SSL certificates.
THX