Milter milter_default_action (default: tempfail)
The default action when a Milter (mail filter) application is unavailable or mis-configured. Specify one of the following: accept Proceed as if the mail filter was not present. reject Reject all further commands in this session with a permanent status code. tempfail Reject all further commands in this session with a temporary status code. quarantine Like "accept", but freeze the message in the "hold" queue. Available with Postfix 2.6 and later.
postconf -e milter_default_action=accept
Postfix Before Queue filter - http://www.postfix.org/SMTPD_PROXY_README.html
HELO sendinghostname This command initiates the SMTP conversation. The host connecting to the remote SMTP server identifies itself by it's fully qualified DNS host name.
EHLO sendinghostname An alternative command for starting the conversation. This states that the sending server wants to use the extended SMTP (ESMTP) protocol.
MAIL From:<source email address> This is the start of an email message. The source email address is what will appear in the "From:" field of the message.
RCPT To:<destination email address> This identifies the receipient of the email message. This command can be repeated multiple times for a given message in order to deliver a single message to multiple receipients.
SIZE=numberofbytes The size command tells the remote sendmail system the size of the attached message in bytes. If ommited, mail readers and delivery agents will try to determine the size of a message based on indicators such as them being terminated by a "." on a line by themselves and headers being sent on a line separated from body text by a blank line. But these methods get confused when you have headers or header like information embedded in messages, attachements, etc.
DATA This command signifies that a stream of data, ie the email message body, will follow. The stream of data is terminated by a "." on a line by itself.
QUIT This terminates an SMTP connection. Multiple email messages can be transfered during a single TCP/IP connection. This allows for more efficient transfer of email. To start another email message in the same session, simply issue another "MAIL" command.
VRFY username This command will request that the receiving SMTP server verify that a given email username is valid. The SMTP server will reply with the login name of the user. This feature can be turned off in sendmail because allowing it can be a security hole. VRFY commands can be used to probe for login names on a system. See the security section below for information about turning off this feature.
EXPN aliasname EXPN is similar to VRFY, except that when used with a distribution list, it will list all users on that list. This can be a bigger problem than the "VRFY" command since sites often have an alias such as "all".
Reply-To: Email header lines are not SMTP commands per se. They are sent in the DATA stream for a message. Header lines appear on a line by themselves, and are seperated from the body of a message by a blank line.
zmprov desc -a zimbraReverseProxySSLToUpstreamEnabled If set as TRUE, proxy will use SSL to connect to the upstream mail servers for web and mail proxy. Note admin console proxy always use https no matter how this attr is set.
zimbraReverseProxyHttpEnabled - Web zimbraReverseProxyMailEnabled - Mail
zimbraReverseProxyPop3StartTlsMode - POP3 clear text login mode - cleartext, starttls, both
zimbraFeaturePop3DataSourceEnabled zimbraPop3CleartextLoginEnabled - Enable clear text login zimbraDataSourceConnectTimeout: 30 zimbraDataSourceConnectionType: cleartext zimbraDataSourceReadTimeout: 60
zimbraFeatureMobileSyncEnabled - Enable Mobile Sync zimbraFeatureMobilePolicyEnabled - Enable Mobile Policy