# phpman > perldoc > Net::SMTP

## NAME
    [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) - Simple Mail Transfer Protocol Client

## SYNOPSIS
        use [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown);

        # Constructors
        $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new('mailhost');
        $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new('mailhost', Timeout => 60);

## DESCRIPTION
    This module implements a client interface to the SMTP and ESMTP protocol, enabling a perl5
    application to talk to SMTP servers. This documentation assumes that you are familiar with the
    concepts of the SMTP protocol described in RFC2821. With [IO::Socket::SSL](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3ASSL/markdown) installed it also
    provides support for implicit and explicit TLS encryption, i.e. SMTPS or SMTP+STARTTLS.

    The [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) class is a subclass of [Net::Cmd](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ACmd/markdown) and (depending on avaibility) of [IO::Socket::IP](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AIP/markdown),
    [IO::Socket::INET6](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AINET6/markdown) or [IO::Socket::INET](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AINET/markdown).

### Class Methods
    "new([$host][, %options])"
        This is the constructor for a new [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) object. $host is the name of the remote host to
        which an SMTP connection is required.

        On failure "undef" will be returned and $@ will contain the reason for the failure.

        $host is optional. If $host is not given then it may instead be passed as the "Host" option
        described below. If neither is given then the "SMTP_Hosts" specified in "[Net::Config](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3AConfig/markdown)" will
        be used.

        %options are passed in a hash like fashion, using key and value pairs. Possible options are:

        Hello - SMTP requires that you identify yourself. This option specifies a string to pass as
        your mail domain. If not given localhost.localdomain will be used.

        SendHello - If false then the EHLO (or HELO) command that is normally sent when constructing
        the object will not be sent. In that case the command will have to be sent manually by
        calling "hello()" instead.

        Host - SMTP host to connect to. It may be a single scalar (hostname[:port]), as defined for
        the "PeerAddr" option in [IO::Socket::INET](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AINET/markdown), or a reference to an array with hosts to try in
        turn. The "host" method will return the value which was used to connect to the host. Format
        - "PeerHost" from [IO::Socket::INET](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AINET/markdown) new method.

        Port - port to connect to. Default - 25 for plain SMTP and 465 for immediate SSL.

        SSL - If the connection should be done from start with SSL, contrary to later upgrade with
        "starttls". You can use SSL arguments as documented in [IO::Socket::SSL](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3ASSL/markdown), but it will usually
        use the right arguments already.

        LocalAddr and LocalPort - These parameters are passed directly to [IO::Socket](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket/markdown) to allow
        binding the socket to a specific local address and port.

        Domain - This parameter is passed directly to [IO::Socket](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket/markdown) and makes it possible to enforce
        IPv4 connections even if [IO::Socket::IP](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AIP/markdown) is used as super class. Alternatively Family can be
        used.

        Timeout - Maximum time, in seconds, to wait for a response from the SMTP server (default:
        120)

        ExactAddresses - If true then all $address arguments must be as defined by "addr-spec" in
        RFC2822. If not given, or false, then [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) will attempt to extract the address from the
        value passed.

        Debug - Enable debugging information

        Example:

            $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new('mailhost',
                                   Hello => 'my.mail.domain',
                                   Timeout => 30,
                                   Debug   => 1,
                                  );

            # the same
            $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new(
                                   Host => 'mailhost',
                                   Hello => 'my.mail.domain',
                                   Timeout => 30,
                                   Debug   => 1,
                                  );

            # the same with direct SSL
            $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new('mailhost',
                                   Hello => 'my.mail.domain',
                                   Timeout => 30,
                                   Debug   => 1,
                                   SSL     => 1,
                                  );

            # Connect to the default server from [Net::config](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3Aconfig/markdown)
            $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new(
                                   Hello => 'my.mail.domain',
                                   Timeout => 30,
                                  );

## Object Methods
    Unless otherwise stated all methods return either a *true* or *false* value, with *true* meaning
    that the operation was a success. When a method states that it returns a value, failure will be
    returned as *undef* or an empty list.

    "[Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)" inherits from "[Net::Cmd](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ACmd/markdown)" so methods defined in "[Net::Cmd](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ACmd/markdown)" may be used to send
    commands to the remote SMTP server in addition to the methods documented here.

    "banner()"
        Returns the banner message which the server replied with when the initial connection was
        made.

    "domain()"
        Returns the domain that the remote SMTP server identified itself as during connection.

    "hello($domain)"
        Tell the remote server the mail domain which you are in using the EHLO command (or HELO if
        EHLO fails). Since this method is invoked automatically when the [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) object is
        constructed the user should normally not have to call it manually.

    "host()"
        Returns the value used by the constructor, and passed to [IO::Socket::INET](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3AINET/markdown), to connect to the
        host.

    "etrn($domain)"
        Request a queue run for the $domain given.

    "starttls(%sslargs)"
        Upgrade existing plain connection to SSL. You can use SSL arguments as documented in
        [IO::Socket::SSL](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3ASSL/markdown), but it will usually use the right arguments already.

    "auth($username, $password)"
    "auth($sasl)"
        Attempt SASL authentication. Requires [Authen::SASL](https://www.chedong.com/phpMan.php/perldoc/Authen%3A%3ASASL/markdown) module. The first form constructs a new
        [Authen::SASL](https://www.chedong.com/phpMan.php/perldoc/Authen%3A%3ASASL/markdown) object using the given username and password; the second form uses the given
        [Authen::SASL](https://www.chedong.com/phpMan.php/perldoc/Authen%3A%3ASASL/markdown) object.

    "mail($address[, %options])"
    "send($address)"
    "send_or_mail($address)"
    "send_and_mail($address)"
        Send the appropriate command to the server MAIL, SEND, SOML or SAML. $address is the address
        of the sender. This initiates the sending of a message. The method "recipient" should be
        called for each address that the message is to be sent to.

        The "mail" method can take some additional ESMTP %options which is passed in hash like
        fashion, using key and value pairs. Possible options are:

         Size        => <bytes>
         Return      => "FULL" | "HDRS"
         Bits        => "7" | "8" | "binary"
         Transaction => <ADDRESS>
         Envelope    => <ENVID>     # xtext-encodes its argument
         ENVID       => <ENVID>     # similar to Envelope, but expects argument encoded
         XVERP       => 1
         AUTH        => <submitter> # encoded address according to RFC 2554

        The "Return" and "Envelope" parameters are used for DSN (Delivery Status Notification).

        The submitter address in "AUTH" option is expected to be in a format as required by RFC
        2554, in an RFC2821-quoted form and xtext-encoded, or <> .

    "reset()"
        Reset the status of the server. This may be called after a message has been initiated, but
        before any data has been sent, to cancel the sending of the message.

    "recipient($address[, $address[, ...]][, %options])"
        Notify the server that the current message should be sent to all of the addresses given.
        Each address is sent as a separate command to the server. Should the sending of any address
        result in a failure then the process is aborted and a *false* value is returned. It is up to
        the user to call "reset" if they so desire.

        The "recipient" method can also pass additional case-sensitive %options as an anonymous hash
        using key and value pairs. Possible options are:

          Notify  => ['NEVER'] or ['SUCCESS','FAILURE','DELAY']  (see below)
          ORcpt   => <ORCPT>
          SkipBad => 1        (to ignore bad addresses)

        If "SkipBad" is true the "recipient" will not return an error when a bad address is
        encountered and it will return an array of addresses that did succeed.

          $smtp->recipient($recipient1,$recipient2);  # Good
          $smtp->recipient($recipient1,$recipient2, { SkipBad => 1 });  # Good
          $smtp->recipient($recipient1,$recipient2, { Notify => ['FAILURE','DELAY'], SkipBad => 1 });  # Good
          @goodrecips=$smtp->recipient(@recipients, { Notify => ['FAILURE'], SkipBad => 1 });  # Good
          $smtp->recipient("$recipient,$recipient2"); # BAD

        Notify is used to request Delivery Status Notifications (DSNs), but your SMTP/ESMTP service
        may not respect this request depending upon its version and your site's SMTP configuration.

        Leaving out the Notify option usually defaults an SMTP service to its default behavior
        equivalent to ['FAILURE'] notifications only, but again this may be dependent upon your
        site's SMTP configuration.

        The NEVER keyword must appear by itself if used within the Notify option and "requests that
        a DSN not be returned to the sender under any conditions."

          {Notify => ['NEVER']}

          $smtp->recipient(@recipients, { Notify => ['NEVER'], SkipBad => 1 });  # Good

        You may use any combination of these three values 'SUCCESS','FAILURE','DELAY' in the
        anonymous array reference as defined by RFC3461 (see <<https://www.ietf.org/rfc/rfc3461.txt>>
        for more information. Note: quotations in this topic from same.).

        A Notify parameter of 'SUCCESS' or 'FAILURE' "requests that a DSN be issued on successful
        delivery or delivery failure, respectively."

        A Notify parameter of 'DELAY' "indicates the sender's willingness to receive delayed DSNs.
        Delayed DSNs may be issued if delivery of a message has been delayed for an unusual amount
        of time (as determined by the Message Transfer Agent (MTA) at which the message is delayed),
        but the final delivery status (whether successful or failure) cannot be determined. The
        absence of the DELAY keyword in a NOTIFY parameter requests that a "delayed" DSN NOT be
        issued under any conditions."

          {Notify => ['SUCCESS','FAILURE','DELAY']}

          $smtp->recipient(@recipients, { Notify => ['FAILURE','DELAY'], SkipBad => 1 });  # Good

        ORcpt is also part of the SMTP DSN extension according to RFC3461. It is used to pass along
        the original recipient that the mail was first sent to. The machine that generates a DSN
        will use this address to inform the sender, because he can't know if recipients get
        rewritten by mail servers. It is expected to be in a format as required by RFC3461,
        xtext-encoded.

    "to($address[, $address[, ...]])"
    "cc($address[, $address[, ...]])"
    "bcc($address[, $address[, ...]])"
        Synonyms for "recipient".

    "data([$data])"
        Initiate the sending of the data from the current message.

        $data may be a reference to a list or a list and must be encoded by the caller to octets of
        whatever encoding is required, e.g. by using the Encode module's "encode()" function.

        If specified the contents of $data and a termination string ".\r\n" is sent to the server.
        The result will be true if the data was accepted.

        If $data is not specified then the result will indicate that the server wishes the data to
        be sent. The data must then be sent using the "datasend" and "dataend" methods described in
        [Net::Cmd](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ACmd/markdown).

    "bdat($data)"
    "bdatlast($data)"
        Use the alternate $data command "BDAT" of the data chunking service extension defined in
        RFC1830 for efficiently sending large MIME messages.

    "expand($address)"
        Request the server to expand the given address Returns an array which contains the text read
        from the server.

    "verify($address)"
        Verify that $address is a legitimate mailing address.

        Most sites usually disable this feature in their SMTP service configuration. Use "Debug =>
        1" option under new() to see if disabled.

    "help([$subject])"
        Request help text from the server. Returns the text or undef upon failure

    "quit()"
        Send the QUIT command to the remote SMTP server and close the socket connection.

    "can_inet6()"
        Returns whether we can use IPv6.

    "can_ssl()"
        Returns whether we can use SSL.

### Addresses
    [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) attempts to DWIM with addresses that are passed. For example an application might
    extract The From: line from an email and pass that to mail(). While this may work, it is not
    recommended. The application should really use a module like [Mail::Address](https://www.chedong.com/phpMan.php/perldoc/Mail%3A%3AAddress/markdown) to extract the mail
    address and pass that.

    If "ExactAddresses" is passed to the constructor, then addresses should be a valid
    rfc2821-quoted address, although [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown) will accept the address surrounded by angle brackets.

     funny user@domain      WRONG
     "funny user"@domain    RIGHT, recommended
     <"funny user"@domain>  OK

## EXAMPLES
    This example prints the mail domain name of the SMTP server known as mailhost:

        #!/usr/local/bin/perl -w

        use [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown);

        $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new('mailhost');
        print $smtp->domain,"\n";
        $smtp->quit;

    This example sends a small message to the postmaster at the SMTP server known as mailhost:

        #!/usr/local/bin/perl -w

        use [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown);

        my $smtp = [Net::SMTP](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ASMTP/markdown)->new('mailhost');

        $smtp->mail($ENV{USER});
        if ($smtp->to('postmaster')) {
         $smtp->data();
         $smtp->datasend("To: postmaster\n");
         $smtp->datasend("\n");
         $smtp->datasend("A simple test message\n");
         $smtp->dataend();
        } else {
         print "Error: ", $smtp->message();
        }

        $smtp->quit;

## EXPORTS
    *None*.

## KNOWN BUGS
    See <<https://rt.cpan.org/Dist/Display.html?Status=Active&Queue=libnet>>.

## SEE ALSO
    [Net::Cmd](https://www.chedong.com/phpMan.php/perldoc/Net%3A%3ACmd/markdown), [IO::Socket::SSL](https://www.chedong.com/phpMan.php/perldoc/IO%3A%3ASocket%3A%3ASSL/markdown).

## AUTHOR
    Graham Barr <<gbarr@pobox.com> <mailto:<gbarr@pobox.com>>>.

    Steve Hay <<shay@cpan.org> <mailto:<shay@cpan.org>>> is now maintaining libnet as of version
    1.22_02.

## COPYRIGHT
    Copyright (C) 1995-2004 Graham Barr. All rights reserved.

    Copyright (C) 2013-2016, 2020 Steve Hay. All rights reserved.

## LICENCE
    This module is free software; you can redistribute it and/or modify it under the same terms as
    Perl itself, i.e. under the terms of either the GNU General Public License or the Artistic
    License, as specified in the LICENCE file.

## VERSION
    Version 3.13

## DATE
    23 Dec 2020

## HISTORY
    See the Changes file.