A new feature in 4.12 is sieve script parsing.
In 4.11 we are able to create sieve script with a GUI.
But we were just able to create it, not re-edit it with GUI.
In 4.12 I implemented sieve script parsing.
So you can create/modify a script with GUI.
Now it’s not necessary to know sieve script language to create/modify script.
GUI supports all sieve extensions:
(see in http://www.iana.org/assignments/sieve-extensions/sieve-extensions.xhtml)
But GUI will show extension when server supports them.
Videos are better than a big text.
Sorry videos are not perfect but I didn’t know a very good program to do it.