NAME¶
msmtp - An SMTP client
SYNOPSIS¶
- Sendmail mode (default):
- msmtp [option...] [--] recipient...
msmtp [option...] -t [--] [recipient...]
- Server information mode:
- msmtp [option...] --serverinfo
- Remote Message Queue Starting mode:
- msmtp [option...] --rmqs=
host|@domain| #queue
DESCRIPTION¶
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.
- --passwordeval=[eval]
- Set your password for SMTP authentication to the output
(stdout) of the execution of eval.
- --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.
- --aliases=[file]
- Set or unset an aliases file. See the aliases
command below.
- --
- 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:
-B
type, -bm, -F
name, -G, -h
N, -i, -L
tag, -m, -n,
-O
option=value, -o
x value
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, scram-sha-1,
cram-md5, gssapi, external, digest-md5,
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 (or in an easily
decryptable form) 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, 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. First, if passwordeval
is set, it will evaluate that command. If passwordeval is not set,
msmtp will try to find the password 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.
- passwordeval [eval]
- Set your password for SMTP authentication to the output
(stdout) of the execution of eval.
- 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, which is stupid but
usually works. Try to change the default if mails get rejected due to
anti-SPAM measures. 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).
- aliases [file]
- Replace local recipients with addresses in the aliases
file. The aliases file is a plain text file containing mappings between a
local address and a list of domain addresses. A local address is defined
as one without an `@' character and a domain address is one with an `@'
character. The mappings are of the form:
local: someone@example.com, person@domain.example
Multiple domain addresses are separated with commas. Comments start with `#'
and continue to the end of the line.
The local address default has special significance and is matched if
the local address is not found in the aliases file. If no default
alias is found, then the local address is left as is.
An empty argument to the aliases command disables the replacement of local
addresses. This is the default.
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
passwordeval gpg -d ~/.msmtp.password.gpg
# Set a default account
account default : provider
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 (but note that you cannot set a password
this way):
set sendmail="/path/to/msmtp --host=mailhub -f me@example.com --tls
--tls-trust-file=trust.crt"
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"
Aliases file
# Example aliases file
# Send root to Joe and Jane
root: joe_smith@example.com, jane_chang@example.com
# Send cron to Mark
cron: mark_jones@example.com
# Send everything else to admin
default: admin@domain.example
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.
SEE ALSO¶
mutt(1),
mail(1),
sendmail(8),
netrc(5) or
ftp(1)