From where can I enable RSS in SMF?

RSS is a technology that is being used by millions of web users around the world to keep track of their favorite websites. RSS feeds enable publishers to syndicate data automatically.
SMF has built-in RSS support and as such, RSS can easily be enabled from SMF’s administrative panel > Main > News and Newsletters > Settings (see the following figure).

Once there, simply check the box next to “Enble XML/RSS news”
The “Maximum message length” field controls the number of maximum characters that the message in the RSS field will have. You can leave this option to the default 255 characters.