SieveEditor
IMAP Sieve filter editor
SieveEditor allows to edit, create, delete sieve scripts.
An application to assist with editing IMAP Sieve filters.
How to install SieveEditor in Ubuntu
If you are on a supported distro, you can install the application through software center by clicking the below link.
If the above link not working, run the below command in terminal to install pim-sieve-editor in Ubuntu
sudo apt install pim-sieve-editor