Send a file to an email address using a bat file without exposing the email info?

Question

I want to send a file to my Gmail account via a bat file and encrypt my email info in that bat file so that if someone opens the bat file they cannot get the email information from it.

Logic such as:

1. check if the internet is working properly

   • if ok send the file and then remove the bat file

2. check if the internet is working properly

   • if no Schedule it to do it later or add it to the start up

   • when done remove it from the Schedule or the start up !

Answer 1

If you need to send an email—even with an attachment—by having a PowerShell script with the logic that builds and sends the email, you can execute it via a batch script passing sensitive values in as arguments rather than hard-coding sensitive values into the script logic.

The PowerShell script logic can accept arguments such as the Gmail local mailbox username, the password to authenticate to send email, and anything else you don't want hard-coded in the script.

• PowerShell Args

  Within a script or function you can refer to unnamed arguments using the $args array, for example passing all the arguments through to a cmdlet. You can also refer to specific arguments by their position:

  "First argument is " + $Args[0]"

  "Second argument is " + $Args[1]"

You can also put logic in the batch script so it too has arguments you can pass sensitive values to it at execution time, and use argument placeholders rather than hard-coding sensitive values.

• Batch Args

  You can get the value of any argument using a % followed by it's numerical position on the command line. The first item passed is always %1 the second item is always %2 and so on

  %* in a batch script refers to all the arguments (e.g. %1 %2 %3 %4 %5 ...%255) only arguments %1 to %9 can be referenced by number.

This way if the scripts are opened, the sensitive values you need to protect will not be exposed or hard-coded into the script logic for anyone to see who may have read access to the script.

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Important Note: There's a section at the bottom of each PowerShell script example name Batch Execute Script that has the logic to use from the batch script to execute or whatever so you will use pass the username, password, and/or attachment full path as the appropriate arguments to the batch script i.e. sendemail.bat "<GmailAccountName>" "<GmailPassword>" "<FullPathAttachment>"

PowerShell Script (no attachment)

$Username      = $args[0]
$EmailPassword = $args[1]

$Username = $Username
$EmailTo = "[e-mail]" 
$EmailFrom = "[e-mail]"
$Subject = "Email Subject"
$Body = "Email Body"
$SMTPServer = "smtp.gmail.com" 
$SMTPMessage = New-Object System.Net.Mail.MailMessage($EmailFrom, $EmailTo, $Subject, $Body)
$SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587) 
$SMTPClient.EnableSsl = $true 
$SMTPClient.Credentials = New-Object System.Net.NetworkCredential($Username, $EmailPassword); 
$SMTPClient.Send($SMTPMessage)

Batch Execute Script

SET GmailAccount=%~1
SET GmailPassword=%~2
SET PowerShellDir=C:\Windows\System32\WindowsPowerShell\v1.0
CD /D "%PowerShellDir%"
Powershell -ExecutionPolicy Bypass -Command "& 'C:\Scripts\SendEmail.ps1' '%GmailAccount%' '%GmailPassword%'"

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PowerShell Script (with attachment)

$Username      = $args[0]
$EmailPassword = $args[1]
$Attachment    = $args[2]

$Username = $Username
$EmailTo = "[e-mail]" 
$EmailFrom = "[e-mail]"
$Subject = "Email Subject"
$Body = "Email Body"
$SMTPServer = "smtp.gmail.com" 
$SMTPMessage = New-Object System.Net.Mail.MailMessage($EmailFrom, $EmailTo, $Subject, $Body)
$Attachment = New-Object System.Net.Mail.Attachment($Attachment)
$SMTPMessage.Attachments.Add($Attachment)
$SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587) 
$SMTPClient.EnableSsl = $true 
$SMTPClient.Credentials = New-Object System.Net.NetworkCredential($Username, $EmailPassword); 
$SMTPClient.Send($SMTPMessage)

Batch Execute Script

SET GmailAccount=%~1
SET GmailPassword=%~2
SET Attachment=%~3
SET PowerShellDir=C:\Windows\System32\WindowsPowerShell\v1.0
CD /D "%PowerShellDir%" 
Powershell -ExecutionPolicy Bypass -Command "& 'C:\Scripts\SendEmail.ps1' '%GmailAccount%' '%GmailPassword%' '%Attachment%'"

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Batch Script (dynamic)

Here's an all-in-one dynamic batch script that you just pass the Gmail account username, the Gmail account password, and the full path to the attachment.

@ECHO OFF

SET GmailAccount=%~1
SET GmailPassword=%~2
SET Attachment=%~3

CALL :PowerShell
CD /D "%PowerShellDir%"
Powershell -ExecutionPolicy Bypass -Command "& '%PSScript%' '%GmailAccount%' '%GmailPassword%' '%Attachment%'"
EXIT

:PowerShell
SET PowerShellDir=C:\Windows\System32\WindowsPowerShell\v1.0
SET PSScript=%temp%\~tmpSendeMail.ps1
IF EXIST "%PSScript%" DEL /Q /F "%PSScript%"

ECHO $Username      = $args[0]>> "%PSScript%"
ECHO $EmailPassword = $args[1]>> "%PSScript%"
ECHO $Attachment    = $args[2]>> "%PSScript%"
ECHO                          >> "%PSScript%"
ECHO $Username    = $Username                 >> "%PSScript%"
ECHO $EmailTo     = "[e-mail]" >> "%PSScript%"
ECHO $EmailFrom   = "[e-mail]" >> "%PSScript%"
ECHO $Subject     = "Email Subject"           >> "%PSScript%"
ECHO $Body        = "Email Body"              >> "%PSScript%"
ECHO $SMTPServer  = "smtp.gmail.com"          >> "%PSScript%"
ECHO $SMTPMessage = New-Object System.Net.Mail.MailMessage($EmailFrom, $EmailTo, $Subject, $Body) >> "%PSScript%"
ECHO $Attachment  = New-Object System.Net.Mail.Attachment($Attachment)                            >> "%PSScript%"
ECHO $SMTPMessage.Attachments.Add($Attachment)                                                    >> "%PSScript%"
ECHO $SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587)                               >> "%PSScript%"
ECHO $SMTPClient.EnableSsl = $true                                                                >> "%PSScript%"
ECHO $SMTPClient.Credentials = New-Object System.Net.NetworkCredential($Username, $EmailPassword) >> "%PSScript%"
ECHO $SMTPClient.Send($SMTPMessage)                                                               >> "%PSScript%"
GOTO :EOF

You execute the batch script like so. . .

 sendemail.bat "<GmailAccountName>" "<GmailPassword>" "<FullPathAttachment>"

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Batch Script (static and self-deleting)

This script will have the hard-coded values set in the variables of GmailAccount=, GmailPassword=, and Attachment= but once executed, it will delete [itself] the script entirely via "%~FN0" where the 0 is the script itself. This means that you will want to be sure you copy this script and then run the copy only from the machine(s) you'll execute where you don't want this information exposed.

@ECHO OFF

SET GmailAccount=<GmailAccountName>
SET GmailPassword=<GmailPassword>
SET Attachment=<FullAttachmentPath>

CALL :PowerShell
CD /D "%PowerShellDir%"
Powershell -ExecutionPolicy Bypass -Command "& '%PSScript%' '%GmailAccount%' '%GmailPassword%' '%Attachment%'"
IF EXIST "%~FN0" DEL /Q /F "%~FN0"
EXIT

:PowerShell
SET PowerShellDir=C:\Windows\System32\WindowsPowerShell\v1.0
SET PSScript=%temp%\~tmpSendeMail.ps1
IF EXIST "%PSScript%" DEL /Q /F "%PSScript%"

ECHO $Username      = $args[0]>> "%PSScript%"
ECHO $EmailPassword = $args[1]>> "%PSScript%"
ECHO $Attachment    = $args[2]>> "%PSScript%"
ECHO                          >> "%PSScript%"
ECHO $Username    = $Username                 >> "%PSScript%"
ECHO $EmailTo     = "[e-mail]" >> "%PSScript%"
ECHO $EmailFrom   = "[e-mail]" >> "%PSScript%"
ECHO $Subject     = "Email Subject"           >> "%PSScript%"
ECHO $Body        = "Email Body"              >> "%PSScript%"
ECHO $SMTPServer  = "smtp.gmail.com"          >> "%PSScript%"
ECHO $SMTPMessage = New-Object System.Net.Mail.MailMessage($EmailFrom, $EmailTo, $Subject, $Body) >> "%PSScript%"
ECHO $Attachment  = New-Object System.Net.Mail.Attachment($Attachment)                            >> "%PSScript%"
ECHO $SMTPMessage.Attachments.Add($Attachment)                                                    >> "%PSScript%"
ECHO $SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587)                               >> "%PSScript%"
ECHO $SMTPClient.EnableSsl = $true                                                                >> "%PSScript%"
ECHO $SMTPClient.Credentials = New-Object System.Net.NetworkCredential($Username, $EmailPassword) >> "%PSScript%"
ECHO $SMTPClient.Send($SMTPMessage)                                                               >> "%PSScript%"
GOTO :EOF

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Further Resources

• MailMessage Constructors
• Attachment Constructors
• SmtpClient Constructors
• SmtpClient.EnableSsl Property
• NetworkCredential Constructors

• SmtpClient.Send Method

• Variable Substitutions (FOR /?)

  In addition, substitution of FOR variable references has been enhanced. You can now use the following optional syntax:

  %~I         - expands %I removing any surrounding quotes (")
  %~nI        - expands %I to a file name only
  %~fI        - expands %I to a fully qualified path name