Hot answers tagged jail
Looking at my /etc/fail2ban/jail.local there is this comment: Since 0.8.1 upstream fail2ban uses sendmail MTA for the mailing. Change mta configuration parameter to mail if you want to revert to conventional 'mail' Based on this and the error you posted, it seems you can only specify sendmail or mail. Do you receive emails from fail2ban when mta is set ...
Only top voted, non community-wiki answers of a minimum length are eligible