Change in new roundcube-config has to be taken care for in the howtos

I used to configure roundcube with:
$config['smtp_host'] = 'localhost';
$config['smtp_port'] = 25;

Because, I don't use roudcube very often, I didn't realize that this config will throw out an SMTP error recently! I tried many things like changing main.cf, master.cf ...but the problem was pretty stupid (if you know it):
Roundcube has no $config['smtp_port'] anymore, they combined it with the host, so if you use $config['smtp_host'] = 'localhost'; it will try to connect with tls automatically. To let it connect over localhost, you have to change it to
$config['smtp_host'] = 'localhost:25';

This seems to work again as it should!

 

First time I noticed was with 1.6.0, so manually installed, not the one that comes with Ubuntu 20.0.4. But I'm not shure, when they did this change.