Install dovecot-antispam by entering the following commands in the terminal:
sudo apt update sudo apt install dovecot-antispam
Dovecot plugins for training spam filters
dovecot-antispam watches designated spam folders and trains mail as spam or not-spam when it moves in or out of those folders respectively. . dovecot-antispam supports dspam, crm114, and generic training by mailing spam and non-spam to training addresses. For crm114, it supports folders for the additional "unsure" classification, and trains when moving from there to spam or normal folders.