SMTPD multiline banner Patch
During postfix's lifetime I have provided a few very minor
patches, which have been accepted by Wietse (with changes).
One patch which I find useful is the SMTP multiline banner
patch. Postfix only supports returning a single line smtp
banner when a client connects on the SMTP port.
This patch allows a system administrator to provide system information
to a remote administrator by adding information to the SMTP banner
his server provides.
The URL for the patch is:
To use this patch /etc/postfix/main.cf must be setup as follows:
# The smtpd_banner parameter specifies the text that follows the 220
# status code in the SMTP greeting banner. Some people like to see
# the mail version advertised. By default, Postfix shows no version.
# You MUST specify the $myhostname at the start of the text. When
# the SMTP client sees its own hostname at the start of an SMTP
# greeting banner it will report a mailer loop. That's better than
# having a machine meltdown.
# Additionally when the smtpd_banner patch is applied multiple lines
# can be sent in the smtpd_banner, each new line separated by the
# sequence "\n" as shown below.
smtpd_banner = $myhostname ESMTP $mail_name\n
System Info: This is a Postfix mail server\n
. running a multiline SMTP greeting patch\n
Further Info: See http://www.postfix.org\n
Site Contact: John Smith, Postmaster\n
Please don't send me SPAM here - we don't like it
# This produces the following SMTP greeting:
# 220-mail.test.com ESMTP Postfix
# 220-System Info: This is a Postfix mail server
# 220-. running a multiline SMTP greeting patch
# 220-Further Info: See http://www.postfix.org
# 220-Site Contact: John Smith, Postmaster
# 220-Email: <email@example.com>
# 220-Telephone: +1-123-456-7890
# 220 Please don't send me SPAM here - we don't like it