If you have created a mailman mailing list called [email protected] and want to clear it, then you will need to remove  Please refer to the following steps to remove mailman archives on cPanel using command. 

1. Run the below command. 
   
   

   cd /usr/local/cpanel/3rdparty/mailman/archives/private

2. There will be many directories at this location. Each directory contains with mailman email list with the example like [email protected] inside the directory listing_example.com.
   
   

   
   drwxr-x---  2 mailman nobody  4.0K Jan 10  2019 mailman/
   
   drwxrwx---  2 mailman mailman 4.0K Jan 10  2019  mailman.mbox/
   
   drwxr-x---  2 mailman nobody  4.0K Oct 25 2019 mail_mailing.com/
   
   drwxrwx---  2 mailman mailman 4.0K Oct 25 2019  mail_mailing.com.mbox/
   
   drwxr-x---  2 mailman nobody  4.0K Oct 25 2019  listing_example.com/
   
   drwxrwx---  2 mailman mailman 4.0K Oct 25 2019  listing_example.mbox/

3. Go to the directory listing_example.com
   
   

   cd listing_example.com

4. List all the content with the below command.
   
   

   ls -alh

5. Run the below command if you want to remove all the archive of 2019.
   
   

   rm 2019* -rf

6. Database and attachments also consist the older data. You can also remove it using the rm-rf command.
   
   
7. Run the below command to clear the mailman cache.
   
   

   /scripts/update_mailman_cache