Mozilla Thunderbird

For setting up your mail @sissa.it using Thunderbird 78, add a new account and fill out the fields Your name, Email address and Password and click Continue:
…verify that the data provided have been accepted by the server and confirm by clicking Done:
Then, in the main pane, right-click on the account that you have just added and choose Settings:
…in the section Copies & Folders CHECK OFF the option Place a copy in Sent Folder…:
…in the section Junk Settings, CHECK OFF the option Enable adaptive junk mail…:
…in the section Syncronizaion & Storage, CHECK OFF the option Keep messages in all folders…: …confirm and close the tab Account Settings.
Again, in the main pane , right-click on the account that you have just added and choose Subscribe…:
…make sure that the folders listed in the pane look like exactly as shown below:
At last, always in the main pane, right-click on the account that you have just added and choose again Settings:
…in the section Server Settings make sure that When I delete a message: is Move it to this folder: and the chosen folder is Deleted Items: …close the tab Account Settings.
Thunderbird is now set up for your email @sissa.it!