In the default sendmail mode, msmtp reads a mail from standard input and sends
it to an SMTP server for delivery.
In server information mode, msmtp prints information about an SMTP server.
In Remote Message Queue Starting mode, msmtp sends a Remote Message Queue
Starting request for a host, domain, or queue to an SMTP server.
EXIT STATUS
The standard sendmail exit status codes are used, as defined in sysexits.h.
OPTIONS
Options override configuration file settings.
They are compatible with sendmail where appropriate.
General options
--version
Print version information. This includes information about the library used for
TLS/SSL support (if any), the library used for authentication, the
authentication mechanisms supported by this library, and the default locations
of the system and user configuration files.
--help
Print help.
-P, --pretend
Print the configuration settings that would be used, but do not take further
action. An asterisk (`*') will be printed instead of your password.
-v, -d, --debug
Print lots of debugging information, including the whole conversation with the
SMTP server. Be careful with this option: the (potentially dangerous) output
will not be sanitized, and your password may get printed in an easily decodable
format!
Changing the mode of operation
-S, --serverinfo
Print information about the SMTP server and exit. This includes information
about supported features (mail size limit, authentication, TLS, DSN, ...) and
about the TLS certificate (if TLS is active).
--rmqs=(host|@domain|#queue)
Send a Remote Message Queue Starting request for the given host, domain, or
queue to the SMTP server and exit.
Configuration options
-C, --file=filename
Use the given file instead of ~/.msmtprc as the user configuration file.
-a, --account=account_name
Use the given account instead of the account named "default". The settings of
this account may be changed with command line options. This option cannot be
used together with the --host option.
--host=hostname
Use this SMTP server with settings from the command line; do not use any
configuration file data. This option cannot be used together with the
--account option.
--port=number
Set the port number to connect to. See the port command below.
--timeout=(off|seconds)
Set a network timeout. See the timeout command below. For compatibility
with older versions, --connect-timeout is accepted as an alias for this
option.
--protocol=(smtp|lmtp)
Set the protocol to use. See the protocol command below.
--auth[=(on|off|method)]
Enable or disable authentication. You can optionally choose the method. See
the auth command below.
--user=[username]
Set or unset the user name for authentication. See the user command
below.
--tls[=(on|off)]
Enable or disable TLS/SSL encryption. See the tls command below.
--tls-starttls[=(on|off)]
Enable or disable STARTTLS for TLS encryption. See the tls_starttls
command below.
--tls-trust-file=[file]
Set or unset a trust file for TLS encryption. See the tls_trust_file
command below.
--tls-crl-file=[file]
Set or unset a certificate revocation list (CRL) file for TLS. See the
tls_crl_file command below.
--tls-fingerprint=[fingerprint]
Set ot unset the fingerprint of a trusted TLS certificate. See the
tls_fingerprint command below.
--tls-key-file=[file]
Set or unset a key file for TLS encryption. See the tls_key_file command
below.
--tls-cert-file=[file]
Set or unset a cert file for TLS encryption. See the tls_cert_file
command below.
--tls-certcheck[=(on|off)]
Enable or disable server certificate checks for TLS encryption. See the
tls_certcheck command below.
--tls-force-sslv3[=(on|off)]
Force TLS/SSL version SSLv3. See the tls_force_sslv3 command below.
--tls-min-dh-prime-bits=[bits]
Set or unset minimum bit size of the Diffie-Hellman (DH) prime. See the
tls_min_dh_prime_bits command below.
--tls-priorities=[priorities]
Set or unset TLS priorities. See the tls_priorities command below.
--domain=[string]
Set the argument of the SMTP EHLO (or LMTP LHLO) command. See the domain
command below.
Options specific to sendmail mode
--auto-from[=(on|off)]
Enable or disable automatic envelope-from addresses. The default is off.
See the auto_from command below.
-f, --from=address
Set the envelope-from address. It is only used when auto_from
is off.
If no account was chosen yet (with --account or --host), this
option will choose the first account that has the given envelope-from address
(set with the from command). If no such account is found, "default" is
used.
--maildomain=[domain]
Set the domain part for generated envelope-from addresses. It is only used when
auto_from is on. See the maildomain command below.
-N, --dsn-notify=(off|cond)
Set or unset DSN notification conditions. See the dsn_notify command
below.
-R, --dsn-return=(off|ret)
Set or unset the DSN notification amount. See the dsn_return command
below.
Note that hdrs is accepted as an alias for headers to be
compatible with sendmail.
--keepbcc[=(on|off)]
Enable or disable the preservation of the Bcc header. See the keepbcc
command below.
-X, --logfile=[file]
Set or unset the log file. See the logfile command below.
--syslog[=(on|off|facility)]
Enable or disable syslog logging. See the syslog command below.
-t, --read-recipients
Read recipient addresses from the To, Cc, and Bcc headers of the mail in
addition to the recipients given on the command line.
If any Resent- headers are present, then the addresses from any Resent-To,
Resent-Cc, and Resent-Bcc headers in the first block of Resent- headers are
used instead.
--read-envelope-from
Read the envelope from address from the From header of the mail.
--
This marks the end of options. All following arguments will be treated as
recipient addresses, even if they start with a `-'.
The following options are accepted but ignored for sendmail compatibility:
-Btype, -bm, -Fname, -G, -hN, -i, -L tag, -m,
-n, -O option=value, -oxvalue
USAGE
Normally, a system wide configuration file and/or a user configuration file
contain information about which SMTP server to use (and how to use it), but
almost all settings can also be configured on the command line.
Information about SMTP servers is organized in accounts. Each account
describes one SMTP server: host name, authentication settings, TLS settings,
and so on. Each configuration file can define multiple accounts.
In sendmail mode, an envelope-from address is necessary to send mail. This is
the mail address that will be presented to the SMTP server as the originator
of the mail.
Envelope-from addresses can be generated automatically (when auto_from
is enabled) or set explicitly with the from command or --from
option. When auto_from is enabled, an envelope-from address of the form
user@domain will be generated. The local part will be set to USER or,
if that fails, to LOGNAME or, if that fails, to the login name of the
current user. The domain part can be set with the maildomain command.
If the maildomain is empty, the envelope-from address will only consist of
the user name and not have a domain part.
The user can choose which account to use in one of three ways:
--account=id
Use the given account. Command line settings override configuration file
settings.
--host=hostname
Use only the settings from the command line; do not use any configuration file
data.
--from=address or --read-envelope-from
Choose the first account from the system or user configuration file that has
a matching envelope-from address as specified by a from command. This
works only when neither --account nor --host is used.
If none of the above options is used (or if no account has a matching
from command), then the account "default" is used.
Skip to the EXAMPLES section for a quick start.
CONFIGURATION FILES
If it exists and is readable, a system wide configuration file
SYSCONFDIR/msmtprc will be loaded, where SYSCONFDIR depends on your platform.
Use --version to find out which directory is used.
If it exists and is readable, a user configuration file will be loaded
(~/.msmtprc by default). Accounts defined in the user configuration file
override accounts from the system configuration file.
The user configuration file must have no more permissions than user read/write.
Configuration data from either file can be changed by command line options.
A configuration file is a simple text file. Empty lines and comment lines
(whose first non-blank character is `#') are ignored.
Every other line must contain a command and may contain an argument to that
command.
The argument may be enclosed in double quotes ("), for example if its first or
last character is a blank.
If the first character of a filename is the tilde (~), this tilde will be
replaced by HOME.
If a command accepts the argument on, it also accepts an empty argument
and treats that as if it was on.
Commands form groups. Each group begins with the account command and
defines the settings for one SMTP server.
Skip to the EXAMPLES section for a quick start.
Commands are as follows:
defaults
Set defaults. The following configuration commands will set default values for
all following account definitions in the current configuration file.
account name [:account[,...]]
Start a new account definition with the given name. The current default values
are filled in.
If a colon and a list of previously defined accounts is given after the account
name, the new account, with the filled in default values, will inherit all
settings from the accounts in the list.
host hostname
The SMTP server to send the mail to.
The argument may be a host name or a network address.
Every account definition must contain this command.
port number
The port that the SMTP server listens on.
The default port will be acquired from your operating system's service database:
for SMTP, the service is "smtp" (default port 25), unless TLS
without STARTTLS is used, in which case it is "ssmtp" (465). For LMTP, it is
"lmtp".
timeout (off|seconds)
Set or unset a network timeout, in seconds. The argument off means that no
timeout will be set, which means that the operating system default will be used.
For compatibility with older versions, connect_timeout is accepted as an
alias for this command.
protocol (smtp|lmtp)
Set the protocol to use. Currently only SMTP and LMTP are supported. SMTP is
the default. See the port command above for default ports.
auto_from [(on|off)]
Enable or disable automatic envelope-from addresses. The default is off.
When enabled, an envelope-from address of the form user@domain will be
generated. The local part will be set to USER or, if that fails, to
LOGNAME or, if that fails, to the login name of the current user. The
domain part can be set with the maildomain command. If the maildomain
is empty, the envelope-from address will only consist of the user name and not
have a domain part. When auto_from is disabled, the envelope-from address must
be set explicitly.
from envelope_from
Set the envelope-from address. This address will only be used when
auto_from is off.
maildomain [domain]
Set a domain part for the generation of an envelope-from address. This is only
used when auto_from is on. The domain may be empty.
auth [(on|off|method)]
This command enables or disables SMTP authentication. You should not need to
set the method yourself; with the argument on, msmtp will choose the best
one available for you (see below).
You probably need to set a username (with user) and password (with
password).
If no password is set but one is needed during authentication, msmtp will try to
find it in ~/.netrc. If that fails, it will try to find it in SYSCONFDIR/netrc
(use --version to find out what SYSCONFDIR is on your platform). If that
fails, it will try to get it from a system specific keyring (if available). If
that fails but a controlling terminal is available, msmtp will prompt you for
it.
Currently supported keyrings are the Gnome Keyring and the Mac OS X Keychain.
The script msmtp-gnome-tool.py can be used to manage Gnome Keyring
passwords for msmtp. To manage Mac OS X Keychain passwords, use the Keychain
Access GUI application. The account name is same as the msmtp user
argument. The keychain item name is smtp://<hostname> where
<hostname> matches the msmtp host argument.
Available authentication methods are plain, cram-md5,
digest-md5, scram-sha-1, gssapi, external,
login, and ntlm.
Note that one or more of these methods may be unavailable due to lack of support
in the underlying authentication library. Use the --version option to
find out which methods are supported.
The plain and login methods send your authentication data in
cleartext over the net, and the ntlm method may be vulnerable to attacks.
These methods should therefore only be used together with the tls command.
If you don't choose the method yourself, msmtp chooses the best secure method
that the SMTP server supports. Secure means that your authentication data will
not be sent in cleartext over the net. For TLS encrypted connections, every
authentication method is secure in this sense. If TLS is not active, only
gssapi, scram-sha-1, digest-md5, and cram-md5 are secure in this sense.
The external is special: the actual authentication happens outside of the
SMTP protocol, typically by sending a TLS client certificate (see the
tls_cert_file command). The external method merely confirms that
this authentication succeeded for the given user (or, if no user name is given,
confirms that authentication succeeded). This authentication method is not
chosen automatically; you have to request it manually.
user [username]
Set your user name for SMTP authentication. An empty argument unsets the user
name. Authentication must be activated with the auth command.
password [secret]
Set your password for SMTP authentication. An empty argument unsets the
password. Authentication must be activated with the auth command.
If no password is set but one is needed during authentication, msmtp will try to
find it in ~/.netrc. If that fails, it will try to find it in SYSCONFDIR/netrc
(use --version to find out what SYSCONFDIR is on your platform). If that
fails, it will try to get it from a system specific keychain (if available). If
that fails but a controlling terminal is available, msmtp will prompt you for
it.
ntlmdomain [domain]
Set a domain for the ntlm authentication method. The default is to use no
domain (equivalent to an empty argument), but some servers seem to require one,
even if it is an arbitrary string.
tls [(on|off)]
This command enables or disables TLS (also known as SSL) encrypted connections
to the SMTP server. Not every server supports TLS.
With TLS/SSL, the connection with the SMTP server will be protected against
eavesdroppers and man-in-the-middle attacks. To use TLS/SSL, it is required to
either use the tls_trust_file command (highly recommended) or to disable
tls_certcheck.
tls_starttls [(on|off)]
By default, TLS encryption is activated using the STARTTLS SMTP command. By
disabling this, TLS encryption is immediately started instead (this is known as
SMTP tunneled through TLS/SSL). The default port is set to 465 for this mode of
operation.
For compatibility with older versions, tls_nostarttls is accepted as an
alias for tls_starttls off.
tls_trust_file [file]
This command activates strict server certificate verification.
The filename must be the absolute path name of a file in PEM format containing
one or more certificates of trusted Certification Authorities (CAs).
On Debian based systems, you can install the ca-certificates package and
use the file /etc/ssl/certs/ca-certificates.crt.
tls_crl_file [file]
This command sets or unsets a certificate revocation list (CRL) file for TLS,
to be used during strict server certificate verification as enabled by the
tls_trust_file command. This allows the verification procedure to detect
revoked certificates.
tls_fingerprint [fingerprint]
This command sets or unsets the fingerprint of a particular TLS certificate.
This certificate will then be trusted, regardless of its contents. This can be
used to trust broken certificates (e.g. with a non-matching hostname) or in
situations where tls_trust_file cannot be used for some reason.
You can give either an SHA1 (recommended) or an MD5 fingerprint in the format
01:23:45:67:...
You can use --serverinfo --tls --tls-certcheck=off to get the peer
certificate's fingerprints.
tls_key_file [file]
This command (together with the tls_cert_file command) enables msmtp to
send a client certificate to the SMTP server if requested.
The file must contain the private key of a certificate in PEM format.
An empty argument disables this feature.
tls_cert_file [file]
This command (together with the tls_key_file command) enables msmtp to
send a client certificate to the SMTP server if requested.
The file must contain a certificate in PEM format.
An empty argument disables this feature.
tls_certcheck [(on|off)]
This command enables or disables checks for the server certificate.
WARNING: When the checks are disabled, TLS/SSL sessions will be vulnerable
to man-in-the-middle attacks!
For compatibility with older versions, tls_nocertcheck is accepted as an
alias for tls_certcheck off.
tls_force_sslv3 [(on|off)]
Force TLS/SSL version SSLv3. This might be needed to use SSL with some old and
broken servers. Do not use this unless you have to.
tls_min_dh_prime_bits [bits]
Set or unset the minimum number of Diffie-Hellman (DH) prime bits that msmtp
will accept for TLS sessions. The default is set by the TLS library and can be
selected by using an empty argument to this command. Only lower the default
(for example to 512 bits) if there is no other way to make TLS work with the
remote server.
tls_priorities [priorities]
Set the priorities for TLS sessions. The default is set by the TLS library and
can be selected by using an empty argument to this command. Currently this
command only works with sufficiently recent GnuTLS releases. See the GnuTLS
documentation of the gnutls_priority_init function for a description of
the priorities string.
dsn_notify (off|condition)
This command sets the condition(s) under which the mail system should send DSN
(Delivery Status Notification) messages. The argument off disables
explicit DSN requests, which means the mail system decides when to send DSN
messages. This is the default.
The condition must be never, to never request notification, or a
comma separated list (no spaces!) of one or more of the following:
failure, to request notification on transmission failure, delay, to
be notified of message delays, success, to be notified of successful
transmission. The SMTP server must support the DSN extension.
dsn_return (off|amount)
This command controls how much of a mail should be returned in DSN (Delivery
Status Notification) messages. The argument off disables explicit DSN
requests, which means the mail system decides how much of a mail it returns in
DSN messages. This is the default.
The amount must be headers, to just return the message headers, or
full, to return the full mail. The SMTP server must support the DSN
extension.
domain argument
Use this command to set the argument of the SMTP EHLO (or LMTP LHLO) command.
The default is localhost (stupid, but working). Possible choices are the
domain part of your mail address (provider.example for joe@provider.example) or
the fully qualified domain name of your host (if available).
keepbcc [(on|off)]
This command controls whether to remove or keep the Bcc header when sending a
mail. The default is to remove it.
logfile [file]
An empty argument disables logging (this is the default).
When logging is enabled by choosing a log file, msmtp will append one line to
the log file for each mail it tries to send via the account that this log file
was chosen for.
The line will include the following information: date and time, host name of the
SMTP server, whether TLS was used, whether authentication was used,
authentication user name (only if authentication is used), envelope-from
address, recipient addresses, size of the mail as transferred to the server
(only if the delivery succeeded), SMTP status code and SMTP error message (only
in case of failure and only if available), error message (only in case of
failure and only if available), exit code (from sysexits.h; EX_OK indicates
success).
If the filename is a dash (-), msmtp prints the log line to the standard
output.
syslog [(on|off|facility)]
Enable or disable syslog logging. The facility can be one of LOG_USER, LOG_MAIL,
LOG_LOCAL0, ..., LOG_LOCAL7. The default is LOG_USER.
Each time msmtp tries to send a mail via the account that contains this syslog
command, it will log one entry to the syslog service with the chosen facility.
The line will include the following information: host name of the SMTP server,
whether TLS was used, whether authentication was used, envelope-from address,
recipient addresses, size of the mail as transferred to the server (only if the
delivery succeeded), SMTP status code and SMTP error message (only in case of
failure and only if available), error message (only in case of failure and only
if available), exit code (from sysexits.h; EX_OK indicates success).
EXAMPLES
Configuration file
# Set default values for all following accounts.
defaults
tls on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
logfile ~/.msmtp.log
# A freemail service
account freemail
host smtp.freemail.example
from joe_smith@freemail.example
auth on
user joe.smith
password secret
# A second mail address at the same freemail service
account freemail2 : freemail
from joey@freemail.example
# The SMTP server of the provider.
account provider
host mail.provider.example
from smithjoe@provider.example
auth on
user 123456789
password my_password
# Set a default account
account default : provider
Manually finding the right CA certificate for tls_trust_file
The following example works as of 2007-04-18.
For the Gmail SMTP server, you first issue the following command:
msmtp --serverinfo --host=smtp.gmail.com --tls=on --port=587--tls-certcheck=off
The option --port=587 is specific to Gmail and should not be used with
other servers. The option --tls-certcheck=off allows msmtp to accept
any certificate, so that it can print some information about it.
According to the output of this command, the common name of the server
certificate issuer is "Thawte Premium Server CA". This means that you have to
trust the Thawte CA to use full TLS security. You can download the Thawte CA
certificate bundle from http://thawte.com/roots. You get a ZIP file with
different certificates. The one you need for the tls_trust_file command is
Thawte Server Roots/ThawtePremiumServerCA_b64.txt.
The following command should now succeed:
msmtp --serverinfo --host=smtp.gmail.com --tls=on --port=587 --tls-trust-file=Thawte Server Roots/ThawtePremiumServerCA_b64.txt
Using msmtp with Mutt
Create a configuration file for msmtp and add the following lines to your
Mutt configuration file:
set sendmail=/path/to/msmtp set use_from=yes set realname=Your Name set from=you@example.com set envelope_from=yes
The envelope_from=yes option lets Mutt use the
-f
option of msmtp. Therefore msmtp chooses the first account that matches
the from address you@example.com.
Alternatively, you can use the
-a
option:
set sendmail=/path/to/msmtp -a my-account
Or set everything from the command line:
set sendmail=/path/to/msmtp --host=mailhub -f me@example.com --tls
If you have multiple mail accounts in your msmtp configuration file
and let Mutt use the
-f
option to choose the right one, you can easily switch accounts in Mutt with
the following Mutt configuration lines:
macro generic <esc>1 :set from=you@example.com macro generic <esc>2 :set from=you@your-employer.example macro generic <esc>3 :set from=you@some-other-provider.example
Using msmtp with mail
Define a default account, and put the following in your ~/.mailrc:
set sendmail=/path/to/msmtp
FILES
SYSCONFDIR/msmtprc
System configuration file. Use
--version
to find out what SYSCONFDIR is on your platform.
~/.msmtprc
User configuration file.
~/.netrc and SYSCONFDIR/netrc
The netrc file contains login information. If a password is not found in the
configuration file, msmtp will search it in ~/.netrc and SYSCONFDIR/netrc before
prompting the user for it. The syntax of netrc files is described in
netrc(5)
or
ftp(1).
ENVIRONMENT
USER, LOGNAME
These variables override the user's login name when constructing an
envelope-from address. LOGNAME is only used if USER is unset.
TMPDIR
Directory to create temporary files in. If this is unset, a system specific
default directory is used.
A temporary file is only created when the
-t/--read-recipients
or
--read-envelope-from
option is used. The file is then used to buffer the headers of the mail (but not
the body, so the file won't get very large).
EMAIL, SMTPSERVER
These environment variables are used only if neither --host nor
--account is used and there is no default account defined in the
configuration files. In this case, the host name is taken from SMTPSERVER, and
the envelope from address is taken from EMAIL, unless overridden by
--from or --read-envelope-from. Currently SMTPSERVER must
contain a plain host name (no URL), and EMAIL must contain a plain address (no
names or additional information).
AUTHORS
msmtp was written by Martin Lambers <marlam@marlam.de>.
Other authors are listed in the AUTHORS file in the source distribution.