open port on firewall for sieve to enable vacation auto-response?

[Patrick Goetz]

I'm trying to set up a vacation auto-response utility for my users, and 
it appears that the path of least resistance is to use the sieverules 
plugin for roundcube (since roundcube is already installed as their 
webmail client alternative to Thunderbird).

In reading through some online hints it appears that I need to open up 
port 4190 on the firewall in order for sieve to work, is this correct?

Source: 
http://www.smartdomotik.com/2015/09/04/how-to-set-filters-in-roundcube-with-sieve/

Also, is there anything special I need to do with my cyrus configuration 
to allow for roundcube to notify imapd about sieve rules being 
activated/deactivated?

BTW, if anyone has a better solution for this, let me know.  The 
criteria are the users need to be able to activate and deactivate the 
vacation auto-response themselves, so writing a sieve script is not an 
option.