smtp-cli is a powerful SMTP
command line client with a support for advanced features, such as STARTTLS, SMTP-AUTH,
or IPv6 and with a scriptable message composition capabilities supporting anything from simple
plain-text messages right up to building complex HTML emails with alternative
plain-text part, attachments and inline images. The MIME-Type of the
attachments can either be guessed automatically or alternatively set on the command line,
separately for each attachment if required.
It's also a convenient tool for testing and debugging SMTP servers' setups. Even
the hardcore mail admins used to typing the SMTP protocol over telnet need a specialised
tool when it comes to verifying encryption settings of their TLS enabled server with a subsequent
user authentication. Such things are pretty hard to type into a telnet session by hand :-)
The name smtp-cli stands for:
smtp-client
smtp-command line interface
Use the script for checking given server's capabilities, test you server's setup or
create and send mails. Command line interface is intuitive, everything is scriptable
and can run in a completely non-interactive mode from various scripts or cron jobs.
It is also ideal for shipping log files from remote machines, running periodical
mail delivery test loops, etc. Also if you ever needed to send a complex email
with attachments from a command line, this script is all you need.
Version 3.10 (2019-10-16)
Use DNS for MX resolution when no --server is given
Version 3.9 (2018-04-06)
Don't attempt to use IO::Socket::INET6 with --ipv4
Version 3.8 (2017-07-05)
New parameter --local-addr
Support body and attachment reading from non-regular files
Various protocol fixes
Version 3.7 (2014-11-21)
Support STDIN input with --body-plain=- or --body-html=-
Version 3.6 (2013-07-11)
Improved compatibility with perl < 5.10 and perl >= 5.18
Added support for more chars in user-part of email address.
Version 3.5 (2013-05-08)
Improved compliance with SMTP RFC 5321.
New parameter --text-encoding
Version 3.4 (2013-02-05)
Support both File::Type and File::LibMagic
for greater compatibility.
Version 3.3 (2012-07-30)
Moved from File::Type to File::LibMagic because
File::Type is no longer available in EPEL for RHEL 6.
Version 3.2 (2012-06-26)
New --add-header, --replace-header and --remove-header options.
Improved compatibility with new IO::Socket::SSL releases. (Corrects the infamous "invalid SSL_version specified at IO/Socket/SSL.pm line 308" error)
Version 3.0 (2012-01-24)
No longer defaults to --server=localhost - update your scripts!
Support for server SSL verification agains CA root cert.
Use "Content-Disposition: attachment" for all attachments unless --attach-inline was used.
Support for --charset=<charset> affecting all text/* parts.
Add "To: undisclosed-recipients:;" if sending only to Bcc.
Version 2.9 (2011-09-02)
Fixed problem with --server wrongly parsing IPv6 addresses.
Version 2.8 (2011-01-05)
Added support for SSMTP aka SMTP/SSL. Turned on by default when --port=465 or explicitly by --ssl.
Version 2.7 (2010-09-08)
Added often requested Cc: and Bcc: support.
Support for "display names" in addresses, for example --from="Some Body <some@body.com>". This works for From, To, Cc and Bcc.
Envelope sender and recipient can be set independently to From: / To: headers with --mail-from and --rcpt-to.
Version 2.6 (2009-08-05)
Message building fixed for plaintext+attachment case.
Auto-enable AUTH as soon as --user parameter is used.
(previously --enable-auth or --auth-plain had to be used together with --user, that was confusing).
New --print-only parameter for displaying the composed MIME message without sending.
All(?) non-standard modules are now optional.
Displays local and remote address on successfull connect.
Version 2.5 (2009-07-21)
Added IPv6 support.
Script renamed from smtp-client.pl to smtp-cli. Why? Just because. ;-)
Version 2.1 (2008-12-08)
Make the MIME modules optional. Simply disable the required functionality if they're not available.
Version 2.0 (2008-11-18)
Support for message building through MIME::Lite, including attachments, multipart, etc.
Version 1.x (released 2003, last updated 2006-08-26)
SMTP debugging tool with STARTTLS and SMTP-AUTH support.
For composing emails you're gonna need an optional
MIME::Lite perl module. See the
download section above for details.
./smtp-cli --from test@domain.com --to user@another.domain.org \
--subject "Simple test with attachments" \
--body-plain "Log files are attached." \
--attach /var/log/some.log@text/plain \
--attach /var/log/other.log
Pretty self-explanatory, isn't it? Standard plain text email with
attachments. The only interesting bit is the syntax used for enforcing
MIME-Type of the second attachment. The syntax
some.log@text/plain will make some.log
attached as text/plain part, while the MIME-Type of
other.log will be guessed by the script and eventually
default to application/octet-stream.
Attachment as an email body
./smtp-cli --from test@domain.com --to user@another.domain.org \
--subject "Image as a mail body" \
--attach /path/to/tux.png
If there is only one text or image file to be sent, the file
itself could be the message body. At the same time it will be
accessible as an attachment with a file name for easy saving. Best to
show a screenshot I guess...
There is no Text or HTML body part and the email is notmultipart/mixed. All that is in the email is
Tux the Penguin image. You can immediately see it in your mailer
but also can easily save it with its provided name tux.png.
The same way it works with text files (or files forced to be
text/plain, to be precise).
Compose a multipart/alternative email with
both HTML and Plain text part and inline images
Sending HTML emails is popular, especially among non-technical
people. They like to change font colours, backgrounds, embed images
and apply all sorts of other useless effects to their one short line
of text. Indeed, me and you are more than happy with plain text and we
both know that some mail readers can't even display colours and
graphics at all (our office manager wouldn't believe!). And therefore
it is a good practice for HTML messages to use
multipart/alternative MIME format with both HTML and TEXT
parts. In this example we're going to go wild and even embed an
inlined image or two into the HTML part.
However first of all prepare the message body. Or bodies,
actually. First one is body.html:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head></head>
<body bgcolor="#ffffff" text="#000000">
<div align="center">
Here comes embedded <font color="#006600"><b>Mr Tux</b></font><br>
<img src="cid:tux.png"><br>
<i>Nice, isn't it?</i><br>
<img src="cid:smiley.png"><br>
</div>
</body>
</html>
Note the <img> tags with cid:filename.xyz
source — that's the way to refer inlined attachments from inside the message.
We will obviously have to inline-attachtux.png and
smiley.png to the message to make it work.
Anyway, the second body file is a plain text representation of the above, call
it body.txt:
Here comes embedded Mr Tux
... actually it doesn't ...
Not in a text-only mail reader.
Sorry
That's it. Here comes the magic command line that puts it all
together:
