254 lines
12 KiB
HTML
254 lines
12 KiB
HTML
<html> <head> </head> <body> <pre>
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SMTP(8) SMTP(8)
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<b>NAME</b>
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smtp - Postfix remote delivery via SMTP
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<b>SYNOPSIS</b>
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<b>smtp</b> [generic Postfix daemon options]
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<b>DESCRIPTION</b>
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The SMTP client processes message delivery requests from
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the queue manager. Each request specifies a queue file, a
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sender address, a domain or host to deliver to, and recip-
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ient information. This program expects to be run from the
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<a href="master.8.html"><b>master</b>(8)</a> process manager.
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The SMTP client updates the queue file and marks recipi-
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ents as finished, or it informs the queue manager that
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delivery should be tried again at a later time. Delivery
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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-
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mon as appropriate.
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The SMTP client looks up a list of mail exchanger
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addresses for the destination host, sorts the list by
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preference, and connects to each listed address until it
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finds a server that responds.
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When the domain or host is specified as a comma/whitespace
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separated list, the SMTP client repeats the above process
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for all destinations until it finds a server that
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responds.
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Once the SMTP client has received the server greeting ban-
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ner, no error will cause it to proceed to the next address
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on the mail exchanger list. Instead, the message is either
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bounced, or its delivery is deferred until later.
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<b>SECURITY</b>
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The SMTP client is moderately security-sensitive. It talks
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to SMTP servers and to DNS servers on the network. The
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SMTP client can be run chrooted at fixed low privilege.
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<b>STANDARDS</b>
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<a href="http://www.faqs.org/rfcs/rfc821.html">RFC 821</a> (SMTP protocol)
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<a href="http://www.faqs.org/rfcs/rfc1651.html">RFC 1651</a> (SMTP service extensions)
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<a href="http://www.faqs.org/rfcs/rfc1870.html">RFC 1870</a> (Message Size Declaration)
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<a href="http://www.faqs.org/rfcs/rfc2197.html">RFC 2197</a> (Pipelining)
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<a href="http://www.faqs.org/rfcs/rfc2554.html">RFC 2554</a> (AUTH command)
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<a href="http://www.faqs.org/rfcs/rfc2821.html">RFC 2821</a> (SMTP protocol)
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<b>DIAGNOSTICS</b>
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Problems and transactions are logged to <b>syslogd</b>(8). Cor-
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rupted message files are marked so that the queue manager
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can move them to the <b>corrupt</b> queue for further inspection.
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Depending on the setting of the <b>notify</b><i>_</i><b>classes</b> parameter,
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the postmaster is notified of bounces, protocol problems,
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and of other trouble.
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<b>BUGS</b>
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<b>CONFIGURATION</b> <b>PARAMETERS</b>
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The following <b>main.cf</b> parameters are especially relevant
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to this program. See the Postfix <b>main.cf</b> file for syntax
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details and for default values. Use the <b>postfix</b> <b>reload</b>
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command after a configuration change.
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<b>Miscellaneous</b>
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<b>best</b><i>_</i><b>mx</b><i>_</i><b>transport</b>
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Name of the delivery transport to use when the
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local machine is the most-preferred mail exchanger
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(by default, a mailer loop is reported, and the
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message is bounced).
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<b>debug</b><i>_</i><b>peer</b><i>_</i><b>level</b>
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Verbose logging level increment for hosts that
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match a pattern in the <b>debug</b><i>_</i><b>peer</b><i>_</i><b>list</b> parameter.
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<b>debug</b><i>_</i><b>peer</b><i>_</i><b>list</b>
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List of domain or network patterns. When a remote
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host matches a pattern, increase the verbose log-
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ging level by the amount specified in the
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<b>debug</b><i>_</i><b>peer</b><i>_</i><b>level</b> parameter.
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<b>disable</b><i>_</i><b>dns</b><i>_</i><b>lookups</b>
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Disable DNS lookups. This means that mail must be
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forwarded via a smart relay host.
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<b>error</b><i>_</i><b>notice</b><i>_</i><b>recipient</b>
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Recipient of protocol/policy/resource/software
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error notices.
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<b>fallback</b><i>_</i><b>relay</b>
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Hosts to hand off mail to if a message destination
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is not found or if a destination is unreachable.
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<b>ignore</b><i>_</i><b>mx</b><i>_</i><b>lookup</b><i>_</i><b>error</b>
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When a name server fails to respond to an MX query,
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search for an A record instead deferring mail
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delivery.
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<b>inet</b><i>_</i><b>interfaces</b>
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The network interface addresses that this mail sys-
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tem receives mail on. When any of those addresses
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appears in the list of mail exchangers for a remote
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destination, the list is truncated to avoid mail
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delivery loops.
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<b>notify</b><i>_</i><b>classes</b>
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When this parameter includes the <b>protocol</b> class,
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send mail to the postmaster with transcripts of
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SMTP sessions with protocol errors.
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<b>smtp</b><i>_</i><b>always</b><i>_</i><b>send</b><i>_</i><b>ehlo</b>
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Always send EHLO at the start of a connection.
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<b>smtp</b><i>_</i><b>never</b><i>_</i><b>send</b><i>_</i><b>ehlo</b>
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Never send EHLO at the start of a connection.
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<b>smtp</b><i>_</i><b>bind</b><i>_</i><b>address</b>
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Numerical source network address to bind to when
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making a connection.
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<b>smtp</b><i>_</i><b>line</b><i>_</i><b>length</b><i>_</i><b>limit</b>
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Length limit for SMTP message content lines. Zero
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means no limit. Some SMTP servers misbehave on
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long lines.
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<b>smtp</b><i>_</i><b>skip</b><i>_</i><b>4xx</b><i>_</i><b>greeting</b>
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Skip servers that greet us with a 4xx status code.
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<b>smtp</b><i>_</i><b>skip</b><i>_</i><b>5xx</b><i>_</i><b>greeting</b>
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Skip servers that greet us with a 5xx status code.
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<b>smtp</b><i>_</i><b>skip</b><i>_</i><b>quit</b><i>_</i><b>response</b>
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Do not wait for the server response after sending
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QUIT.
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<b>smtp</b><i>_</i><b>pix</b><i>_</i><b>workaround</b><i>_</i><b>delay</b><i>_</i><b>time</b>
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The time to pause before sending .<CR><LF>, while
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working around the CISCO PIX firewall
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<CR><LF>.<CR><LF> bug.
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<b>smtp</b><i>_</i><b>pix</b><i>_</i><b>workaround</b><i>_</i><b>threshold</b><i>_</i><b>time</b>
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The time a message must be queued before the CISCO
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PIX firewall <CR><LF>.<CR><LF> bug workaround is
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turned on.
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<b>Authentication</b> <b>controls</b>
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<b>smtp</b><i>_</i><b>sasl</b><i>_</i><b>auth</b><i>_</i><b>enable</b>
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Enable per-session authentication as per <a href="http://www.faqs.org/rfcs/rfc2554.html">RFC 2554</a>
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(SASL). By default, Postfix is built without SASL
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support.
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<b>smtp</b><i>_</i><b>sasl</b><i>_</i><b>password</b><i>_</i><b>maps</b>
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Lookup tables with per-host or domain <i>name</i>:<i>password</i>
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entries. No entry for a host means no attempt to
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authenticate.
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<b>smtp</b><i>_</i><b>sasl</b><i>_</i><b>security</b><i>_</i><b>options</b>
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Zero or more of the following.
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<b>noplaintext</b>
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Disallow authentication methods that use
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plaintext passwords.
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<b>noactive</b>
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Disallow authentication methods that are
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vulnerable to non-dictionary active attacks.
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<b>nodictionary</b>
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Disallow authentication methods that are
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vulnerable to passive dictionary attack.
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<b>noanonymous</b>
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Disallow anonymous logins.
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<b>Resource</b> <b>controls</b>
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<b>smtp</b><i>_</i><b>destination</b><i>_</i><b>concurrency</b><i>_</i><b>limit</b>
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Limit the number of parallel deliveries to the same
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destination. The default limit is taken from the
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<b>default</b><i>_</i><b>destination</b><i>_</i><b>concurrency</b><i>_</i><b>limit</b> parameter.
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<b>smtp</b><i>_</i><b>destination</b><i>_</i><b>recipient</b><i>_</i><b>limit</b>
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Limit the number of recipients per message deliv-
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ery. The default limit is taken from the
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<b>default</b><i>_</i><b>destination</b><i>_</i><b>recipient</b><i>_</i><b>limit</b> parameter.
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<b>Timeout</b> <b>controls</b>
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The default time unit is seconds; an explicit time unit
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can be specified by appending a one-letter suffix to the
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value: s (seconds), m (minutes), h (hours), d (days) or w
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(weeks).
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<b>smtp</b><i>_</i><b>connect</b><i>_</i><b>timeout</b>
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Timeout for completing a TCP connection. When no
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connection can be made within the deadline, the
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SMTP client tries the next address on the mail
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exchanger list.
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<b>smtp</b><i>_</i><b>helo</b><i>_</i><b>timeout</b>
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Timeout for receiving the SMTP greeting banner.
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When the server drops the connection without send-
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ing a greeting banner, or when it sends no greeting
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banner within the deadline, the SMTP client tries
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the next address on the mail exchanger list.
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<b>smtp</b><i>_</i><b>helo</b><i>_</i><b>timeout</b>
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Timeout for sending the <b>HELO</b> command, and for
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receiving the server response.
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<b>smtp</b><i>_</i><b>mail</b><i>_</i><b>timeout</b>
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Timeout for sending the <b>MAIL</b> <b>FROM</b> command, and for
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receiving the server response.
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<b>smtp</b><i>_</i><b>rcpt</b><i>_</i><b>timeout</b>
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Timeout for sending the <b>RCPT</b> <b>TO</b> command, and for
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receiving the server response.
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<b>smtp</b><i>_</i><b>data</b><i>_</i><b>init</b><i>_</i><b>timeout</b>
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Timeout for sending the <b>DATA</b> command, and for
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receiving the server response.
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<b>smtp</b><i>_</i><b>data</b><i>_</i><b>xfer</b><i>_</i><b>timeout</b>
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Timeout for sending the message content.
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<b>smtp</b><i>_</i><b>data</b><i>_</i><b>done</b><i>_</i><b>timeout</b>
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Timeout for sending the "<b>.</b>" command, and for
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receiving the server response. When no response is
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received, a warning is logged that the mail may be
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delivered multiple times.
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<b>smtp</b><i>_</i><b>quit</b><i>_</i><b>timeout</b>
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Timeout for sending the <b>QUIT</b> command, and for
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receiving the server response.
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<b>SEE</b> <b>ALSO</b>
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<a href="bounce.8.html">bounce(8)</a> non-delivery status reports
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<a href="master.8.html">master(8)</a> process manager
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<a href="qmgr.8.html">qmgr(8)</a> queue manager
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syslogd(8) system logging
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<b>LICENSE</b>
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The Secure Mailer license must be distributed with this
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software.
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<b>AUTHOR(S)</b>
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Wietse Venema
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IBM T.J. Watson Research
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P.O. Box 704
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Yorktown Heights, NY 10598, USA
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SMTP(8)
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</pre> </body> </html>
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