HazteK Software

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Network / SMTP Mail Sender → 👍 18 👎 3
SMTP Mail Sender is an application that allows you to send messages through an SMTP server. It lets you send messages if you do not have a mail application installed, or need to send from an account that is only used for sending messages without worrying about responses. It also runs from a USB thumb drive, so you can send emails from anywhere you have access to a computer with Internet access.
Due to changes in security postures, SMTP Mail Sender, and other applications available on this site that send email no longer work with major free email service providers, like Gmail, Yahoo, Microsoft, etc. It will still happily work with private email servers that still accept standard SMTP traffic/authentication.

  • Graphical user interface (GUI) instead of the run of the mill command line applications. UI allows customization by showing/hiding fields as necessary.
  • If you need a true command line application that does not display a user interface, I highly recommend Blat.
  • Built in address book saves you time typing email addresses, guesses and auto-completes addresses already in the address book
  • Send messages using a SMTP server from any Internet connected computer from a thumb drive
  • Supports attaching an unlimited amount of files to the message before sending
  • Sends plain text messages to minimize bandwidth used for processing the messages as they travel across the Internet.
  • Includes language support for English, French, Italian and Spanish
  • Send messages automatically from a script using command line parameters. A GUI dialog will still pop up when automatically sending the message.
SMTP Mail Sender - Add Multiple AddressesSMTP Mail Sender Main Interface
The following items are required for SMTP Mail Sender to run properly.
Supported/Tested Operating Systems
The following operating systems are supported for running SMTP Mail Sender. It may run on other operating systems, but I have not tested any except the ones listed.
Like SMTP Mail Sender and want to support me? 🍕 Buy me some pizza!
Version Information

The current version of SMTP Mail Sender is See the change log.

Frequently Asked Questions
How can I get this to work with [big email provider]?
Unfortunately as time moves on, free applications like this are pushed out of the market by stricter and stricter security requirements. If you run your own mail server, this application will probably still work for you. If you are trying to interface with one of the larger email providers like Gmail, it is unlikely to work properly. Being a free application, it's just not worth the effort to implement the current flavor of security for email. It's unfortunate, but that's the way it is these days. 😢
Does SMTP Mail Sender work with SendGrid?
Yes. I have confirmed that you can send emails through SendGrid using their SMTP Relay integration. After creating an API key to use with SMTP Mail Sender, use these settings:
Server: smtp.sendgrid.net
Port: 587
TLS: checked
Username: apikey
Password: YOUR_API_KEY
Can I automate sending messages using a script of some sort?
Yes! SMTP Mail Sender supports basic commands for scripting. You can call the application from a batch script or any other scripting language available in Windows. From the Command Line Arguments section of the readme file:
Command Line Arguments

SMTP Mail Sender accepts command line arguments. To send command arguments with
spaces, you need to enclose the argument in a space, i.e.

-subject "This is my cool subject" -from user@example.org

The following arguments are currently supported:

-a, -attachment               - This attaches the specified file to the message.
You can use multiple -a arguments to add more
than one attachment on a single message.
-b, -body, -message, -msg  - This puts whatever you supply at the command line
into the message body. You can also supply a file
name and if the file exists, will load that into
the body of the message.
-c, -config                - This loads the configuration file specified, not
the config.conf file in the application directory.
-f, -from                  - Sets the from field
-g, -log                   - Log to smtpsend.log in "start in" directory
-logfile                   - Override the log file path & name, example:
-logfile C:\Windows\Logs\smtpsend.log
-l, -language              - Loads the language file that is passed in. The
language files can be found in the .\lang folder.
example: -l lang\lang.es.txt will load Spanish
-s, -subject               - Sets the subject field
-send                      - Automatically send the message after filling in
all the fields specified with other arguments.
(Note: the application must be configured before
this will work properly.)
-t, -to                    - Sets the to field. Separate addresses with a comma
-cc                        - Sets the CC field.
-bcc                       - Sets the BCC field.
-username                  - Pass in a plain text username to authenticate with
-password                  - Pass in a plain text password to authenticate with
-timeout                   - Sets the SMTP timeout in seconds. Default is 100.
Does it support encryption?
SMTP Mail Sender supports Transport Layer Security, in the form of STARTTLS. This encrypts the data as it traverses between your client and the mail server. It does not, however, encrypt the contents of the message. Anyone who has access to the server(s) in which the email passes through could potentially view the contents.
Why are my messages not being sent/delivered?
Make sure you have your mail settings configured properly (see above). Also, make sure the receiving end is not sending your messages to the spam/junk email folder. If you are still having issues, check the configuration option to enable logging to a file, if it?s not already, and then look through the log to see if any more information can lead you towards a resolution. You may also want to investigate whether your ISP blocks traffic on specific ports. Port 25 is a common port to be blocked, due to spam relaying issues.
Does it support HTML messages?
No. It is not designed to be a complete email replacement.
Will it ever support HTML messages?
No. It is not designed to be a complete email replacement.
None of these responses resolved my issue, can I contact you?
Definitely! If you are still having issues getting your client configured and you would like help, get in contact with me and I?ll do my best to help you out.
When I try to launch the application on a newer version of Windows (8+) it gives me an error. What could cause this?
The most likely answer is that you do not have the .NET 2.0 framework installed. It's not enabled by default on newer versions of Windows. You can either enable the .NET 2.0/3.5 framework, or you can download the new version of SMTP Mail Sender that is compiled against the .NET 4.6 framework available on this page.
August 27, 2021
Hi, Joey,
I forgot how to hide the Reply-To label and field
in the hide.txt file.
Joey Hazlett
August 27, 2021
Hi Wolf,

You just need to edit the hide.txt file and remove the two # characters in front of the ReplyTo field objects:
# "Reply-To" label and input box
# "Reply-To" label and input box
July 17, 2020
Hi Joey,
I am trying to send an email with the following command line.But your madness creates an error. What did I do wrong? Is the% date% format not supported? :
"C:\iFix Project\SSI01\APP\SMTP\APP_2020\SMTPMailSender.exe" -subject "Daily Report" -from "somewhere@somewehere.com" -to "somewhere@somewehere.com" -attachment "D:\Proficy\Dailyreport\SILOS\%date% Daily Report Silo 1" -body "Automation Report" -send

regards, Sascha
Joey Hazlett
July 17, 2020
Hi Sascha,

When I do the following, it reports a date in an invalid file format:
C:\Users\Joey>echo %date%
Fri 07/17/2020

Since those forward slashes are in the variable, I think that is what would cause this problem. If you have a date format that doesn't use the slashes, then it may be literally reading %date% as a string, and looking for a directory of the same name. While that is a valid file format, I highly doubt you have a directory named %date% containing your files. :)
July 13, 2020
How do I attach a file automatically?
It is always the same file.
Joey Hazlett
July 13, 2020
You would just include -a "C:\path\to\the\file.txt" on your command line, and it will attach the file immediately upon loading.
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