<html> <head> </head> <body> <pre> SMTP(8) SMTP(8) <b>NAME</b> smtp - Postfix remote delivery via SMTP <b>SYNOPSIS</b> <b>smtp</b> [generic Postfix daemon options] <b>DESCRIPTION</b> The SMTP client processes message delivery requests from the queue manager. Each request specifies a queue file, a sender address, a domain or host to deliver to, and recip- ient information. This program expects to be run from the <a href="master.8.html"><b>master</b>(8)</a> process manager. The SMTP client updates the queue file and marks recipi- ents as finished, or it informs the queue manager that delivery should be tried again at a later time. Delivery problem reports are sent to the <a href="bounce.8.html"><b>bounce</b>(8)</a> or <a href="defer.8.html"><b>defer</b>(8)</a> dae- mon as appropriate. The SMTP client looks up a list of mail exchanger addresses for the destination host, sorts the list by preference, and connects to each listed address until it finds a server that responds. When the domain or host is specified as a comma/whitespace separated list, the SMTP client repeats the above process for all destinations until it finds a server that responds. Once the SMTP client has received the server greeting ban- ner, no error will cause it to proceed to the next address on the mail exchanger list. Instead, the message is either bounced, or its delivery is deferred until later. <b>SECURITY</b> The SMTP client is moderately security-sensitive. It talks to SMTP servers and to DNS servers on the network. The SMTP client can be run chrooted at fixed low privilege. <b>STANDARDS</b> <a href="http://www.faqs.org/rfcs/rfc821.html">RFC 821</a> (SMTP protocol) <a href="http://www.faqs.org/rfcs/rfc822.html">RFC 822</a> (ARPA Internet Text Messages) <a href="http://www.faqs.org/rfcs/rfc1651.html">RFC 1651</a> (SMTP service extensions) <a href="http://www.faqs.org/rfcs/rfc1652.html">RFC 1652</a> (8bit-MIME transport) <a href="http://www.faqs.org/rfcs/rfc1870.html">RFC 1870</a> (Message Size Declaration) <a href="http://www.faqs.org/rfcs/rfc2045.html">RFC 2045</a> (MIME: Format of Internet Message Bodies) <a href="http://www.faqs.org/rfcs/rfc2046.html">RFC 2046</a> (MIME: Media Types) <a href="http://www.faqs.org/rfcs/rfc2554.html">RFC 2554</a> (AUTH command) <a href="http://www.faqs.org/rfcs/rfc2821.html">RFC 2821</a> (SMTP protocol) <a href="http://www.faqs.org/rfcs/rfc2920.html">RFC 2920</a> (SMTP Pipelining) <b>DIAGNOSTICS</b> Problems and transactions are logged to <b>syslogd</b>(8). Cor- rupted message files are marked so that the queue manager can move them to the <b>corrupt</b> queue for further inspection. Depending on the setting of the <b>notify</b><i>_</i><b>classes</b> parameter, the postmaster is notified of bounces, protocol problems, and of other trouble. <b>BUGS</b> <b>CONFIGURATION</b> <b>PARAMETERS</b> The following <b>main.cf</b> parameters are especially relevant to this program. See the Postfix <b>main.cf</b> file for syntax details and for default values. Use the <b>postfix</b> <b>reload</b> command after a configuration change. <b>Miscellaneous</b> <b>best</b><i>_</i><b>mx</b><i>_</i><b>transport</b> Name of the delivery transport to use when the local machine is the most-preferred mail exchanger (by default, a mailer loop is reported, and the message is bounced). <b>debug</b><i>_</i><b>peer</b><i>_</i><b>level</b> Verbose logging level increment for hosts that match a pattern in the <b>debug</b><i>_</i><b>peer</b><i>_</i><b>list</b> parameter. <b>debug</b><i>_</i><b>peer</b><i>_</i><b>list</b> List of domain or network patterns. When a remote host matches a pattern, increase the verbose log- ging level by the amount specified in the <b>debug</b><i>_</i><b>peer</b><i>_</i><b>level</b> parameter. <b>disable</b><i>_</i><b>dns</b><i>_</i><b>lookups</b> Disable DNS lookups. This means that mail must be forwarded via a smart relay host. <b>error</b><i>_</i><b>notice</b><i>_</i><b>recipient</b> Recipient of protocol/policy/resource/software error notices. <b>fallback</b><i>_</i><b>relay</b> Hosts to hand off mail to if a message destination is not found or if a destination is unreachable. <b>ignore</b><i>_</i><b>mx</b><i>_</i><b>lookup</b><i>_</i><b>error</b> When a name server fails to respond to an MX query, search for an A record instead deferring mail delivery. <b>inet</b><i>_</i><b>interfaces</b> The network interface addresses that this mail sys- tem receives mail on. When any of those addresses appears in the list of mail exchangers for a remote destination, the list is truncated to avoid mail delivery loops. See also the <b>proxy</b><i>_</i><b>interfaces</b> parameter. <b>notify</b><i>_</i><b>classes</b> When this parameter includes the <b>protocol</b> class, send mail to the postmaster with transcripts of SMTP sessions with protocol errors. <b>proxy</b><i>_</i><b>interfaces</b> Network interfaces that this mail system receives mail on by way of a proxy or network address trans- lator. When any of those addresses appears in the list of mail exchangers for a remote destination, the list is truncated to avoid mail delivery loops. See also the <b>inet</b><i>_</i><b>interfaces</b> parameter. <b>smtp</b><i>_</i><b>always</b><i>_</i><b>send</b><i>_</i><b>ehlo</b> Always send EHLO at the start of a connection. <b>smtp</b><i>_</i><b>never</b><i>_</i><b>send</b><i>_</i><b>ehlo</b> Never send EHLO at the start of a connection. <b>smtp</b><i>_</i><b>bind</b><i>_</i><b>address</b> Numerical source network address to bind to when making a connection. <b>smtp</b><i>_</i><b>line</b><i>_</i><b>length</b><i>_</i><b>limit</b> Length limit for SMTP message content lines. Zero means no limit. Some SMTP servers misbehave on long lines. <b>smtp</b><i>_</i><b>helo</b><i>_</i><b>name</b> The hostname to be used in HELO and EHLO commands. <b>smtp</b><i>_</i><b>skip</b><i>_</i><b>4xx</b><i>_</i><b>greeting</b> Skip servers that greet us with a 4xx status code. <b>smtp</b><i>_</i><b>skip</b><i>_</i><b>5xx</b><i>_</i><b>greeting</b> Skip servers that greet us with a 5xx status code. <b>smtp</b><i>_</i><b>skip</b><i>_</i><b>quit</b><i>_</i><b>response</b> Do not wait for the server response after sending QUIT. <b>smtp</b><i>_</i><b>pix</b><i>_</i><b>workaround</b><i>_</i><b>delay</b><i>_</i><b>time</b> The time to pause before sending .<CR><LF>, while working around the CISCO PIX firewall <CR><LF>.<CR><LF> bug. <b>smtp</b><i>_</i><b>pix</b><i>_</i><b>workaround</b><i>_</i><b>threshold</b><i>_</i><b>time</b> The time a message must be queued before the CISCO PIX firewall <CR><LF>.<CR><LF> bug workaround is turned on. <b>MIME</b> <b>Conversion</b> <b>disable</b><i>_</i><b>mime</b><i>_</i><b>output</b><i>_</i><b>conversion</b> Disable the conversion of 8BITMIME format to 7BIT format when the remote system does not advertise 8BITMIME support. <b>mime</b><i>_</i><b>boundary</b><i>_</i><b>length</b><i>_</i><b>limit</b> The amount of space that will be allocated for MIME multipart boundary strings. The MIME processor is unable to distinguish between boundary strings that do not differ in the first <b>$mime</b><i>_</i><b>bound-</b> <b>ary</b><i>_</i><b>length</b><i>_</i><b>limit</b> characters. <b>mime</b><i>_</i><b>nesting</b><i>_</i><b>limit</b> The maximal nesting level of multipart mail that the MIME processor can handle. Refuse mail that is nested deeper, when converting from 8BITMIME format to 7BIT format. <b>Authentication</b> <b>controls</b> <b>smtp</b><i>_</i><b>sasl</b><i>_</i><b>auth</b><i>_</i><b>enable</b> Enable per-session authentication as per <a href="http://www.faqs.org/rfcs/rfc2554.html">RFC 2554</a> (SASL). By default, Postfix is built without SASL support. <b>smtp</b><i>_</i><b>sasl</b><i>_</i><b>password</b><i>_</i><b>maps</b> Lookup tables with per-host or domain <i>name</i>:<i>password</i> entries. No entry for a host means no attempt to authenticate. <b>smtp</b><i>_</i><b>sasl</b><i>_</i><b>security</b><i>_</i><b>options</b> Zero or more of the following. <b>noplaintext</b> Disallow authentication methods that use plaintext passwords. <b>noactive</b> Disallow authentication methods that are vulnerable to non-dictionary active attacks. <b>nodictionary</b> Disallow authentication methods that are vulnerable to passive dictionary attack. <b>noanonymous</b> Disallow anonymous logins. <b>Resource</b> <b>controls</b> <b>smtp</b><i>_</i><b>destination</b><i>_</i><b>concurrency</b><i>_</i><b>limit</b> Limit the number of parallel deliveries to the same destination. The default limit is taken from the <b>default</b><i>_</i><b>destination</b><i>_</i><b>concurrency</b><i>_</i><b>limit</b> parameter. <b>smtp</b><i>_</i><b>destination</b><i>_</i><b>recipient</b><i>_</i><b>limit</b> Limit the number of recipients per message deliv- ery. The default limit is taken from the <b>default</b><i>_</i><b>destination</b><i>_</i><b>recipient</b><i>_</i><b>limit</b> parameter. <b>Timeout</b> <b>controls</b> The default time unit is seconds; an explicit time unit can be specified by appending a one-letter suffix to the value: s (seconds), m (minutes), h (hours), d (days) or w (weeks). <b>smtp</b><i>_</i><b>connect</b><i>_</i><b>timeout</b> Timeout for completing a TCP connection. When no connection can be made within the deadline, the SMTP client tries the next address on the mail exchanger list. <b>smtp</b><i>_</i><b>helo</b><i>_</i><b>timeout</b> Timeout for receiving the SMTP greeting banner. When the server drops the connection without send- ing a greeting banner, or when it sends no greeting banner within the deadline, the SMTP client tries the next address on the mail exchanger list. <b>smtp</b><i>_</i><b>helo</b><i>_</i><b>timeout</b> Timeout for sending the <b>HELO</b> command, and for receiving the server response. <b>smtp</b><i>_</i><b>mail</b><i>_</i><b>timeout</b> Timeout for sending the <b>MAIL</b> <b>FROM</b> command, and for receiving the server response. <b>smtp</b><i>_</i><b>rcpt</b><i>_</i><b>timeout</b> Timeout for sending the <b>RCPT</b> <b>TO</b> command, and for receiving the server response. <b>smtp</b><i>_</i><b>data</b><i>_</i><b>init</b><i>_</i><b>timeout</b> Timeout for sending the <b>DATA</b> command, and for receiving the server response. <b>smtp</b><i>_</i><b>data</b><i>_</i><b>xfer</b><i>_</i><b>timeout</b> Timeout for sending the message content. <b>smtp</b><i>_</i><b>data</b><i>_</i><b>done</b><i>_</i><b>timeout</b> Timeout for sending the "<b>.</b>" command, and for receiving the server response. When no response is received, a warning is logged that the mail may be delivered multiple times. <b>smtp</b><i>_</i><b>quit</b><i>_</i><b>timeout</b> Timeout for sending the <b>QUIT</b> command, and for receiving the server response. <b>SEE</b> <b>ALSO</b> <a href="bounce.8.html">bounce(8)</a> non-delivery status reports <a href="master.8.html">master(8)</a> process manager <a href="qmgr.8.html">qmgr(8)</a> queue manager syslogd(8) system logging <b>LICENSE</b> The Secure Mailer license must be distributed with this software. <b>AUTHOR(S)</b> Wietse Venema IBM T.J. Watson Research P.O. Box 704 Yorktown Heights, NY 10598, USA SMTP(8) </pre> </body> </html>