# Fail2Ban filter to block relay attempts though a Courier smtp server # # [INCLUDES] # Read common prefixes. If any customizations available -- read them from # common.local before = common.conf [Definition] _daemon = courieresmtpd failregex = ^%(__prefix_line)serror,relay=,.*: 550 User (<.*> )?unknown\.?$ ^%(__prefix_line)serror,relay=,msg="535 Authentication failed\.",cmd:( AUTH \S+)?( [0-9a-zA-Z\+/=]+)?$ ignoreregex = # Author: Cyril Jaquier