# /etc/postfix/helo_checks 2011-07-15

!/[[:alpha:]]/		501 5.5.2
	We find that all-numeric EHLO/HELO greetings are usually spam.
	If not, please ask your postmaster to correct the server's
	EHLO/HELO greeting.
!/\./			501 5.5.2
	We find that non-qualified EHLO/HELO greetings are usually spam.
	If not, please ask your postmaster to correct the server's
	EHLO/HELO greeting.
/\.(l(an|ocal)|invalid|home)$/	REJECT Invalid HELO name is a spam sign.

# It's often useful to add your own domain/hostname here too. This is
# deliberately left unanchored, because the appearance of this string
# inside any EHLO/HELO would be highly suspicious.
/myhostname\.example\.org/	REJECT You are not me

# If other hosts in your domain send mail to you, they should either be
# whitelisted before this check, or don't use this
/example\.org$/			REJECT You are not allowed to use the
	example.org domain name.