Roundcube + Let's Encrypt (multi-domain)

Hi, I have been searching for this for a while now, but didn't find an answer. If I missed something please just direct me to some right resources if possible.
I am running the perfect server setup on Debian 9 and want to be able to support multiple domain emails with Let's Encrypt SSL. (Currently most emails just go straight to spam on gmail).
Would something like this work (%s):

Code:

// IMAP socket context options
// See http://php.net/manual/en/context.ssl.php
// The example below enables server certificate validation
$config['imap_conn_options'] = array(
'ssl' => array(
'verify_peer' => true,
'verify_depth' => 3,
'cafile' => '/etc/letsencrypt/live/%s/fullchain.pem',
),
);
// SMTP socket context options
// See http://php.net/manual/en/context.ssl.php
// The example below enables server certificate validation, and
// requires 'smtp_timeout' to be non zero.
$config['smtp_conn_options'] = array(
'ssl' => array(
'verify_peer' => true,
'verify_depth' => 3,
'cafile' => '/etc/letsencrypt/live/%s/fullchain.pem',
),
);

Or should I actually add the SSL on postfix somehow? I am quite new at managing servers, pardon ^^

 

Is your question about how to make postfix use the LE certificate you have?
I know how to do that when host is running ISPConfig, but my guess is if you have created LE certificate manually for your mail host FQDN, you can use similar method to make other services use that certificate:
https://www.howtoforge.com/tutorial...e-lets-encrypt-ssl-certificate/#a-for-postfix

 

I honestly just outsourced my email to an external provider, until I will be able to be sure I can manage the mail service securely.
This also makes sense if the server goes down, I can at least have access to e-mails and talk to customers.