UNBLOG Tutorials

VBScript Message-Box (MsgBox) Logon

The Visual Basic Script Message-Box (MsgBox) function is excellent for this purpose. Insert the following 3 lines into an editor (Notepad) and save them as i.e. “logon.bat”.

echo msgbox("Good morning staff. we serve coffee or tea in the lounge bar. Thank you and a nice day!"),vbInformation ,"Message"> %temp%\msg.vbs %temp%\msg.vbs erase %temp%\msg.vbs

This VB-Script creates a pop-up window with information through the MsgBox function. The msg.vbs file is saved under %temp% and erase them after execution.

The user can close the opened window by clicking OK.

User Logon script (dsa.msc)

In the AD user administration (dsa.msc) for the corresponding users, enter the file name in the Profile tab at Logon script (logon.bat).

For Windows domain, save the file to \\server\netlogon.

The netlogon share is located on the server at %systemroot%\SYSVOL\sysvol\[domain]\scripts. If a logon script is already in use, the code lines can be inserted into this script.

Microsoft Visual Basic Scripting Edition

VBScript (“Microsoft Visual Basic Scripting Edition”) is an Active Scripting language developed by Microsoft that is modeled on Visual Basic. It allows Microsoft Windows system administrators to generate powerful tools for managing computers without error handling and with subroutines and other advanced programming constructs. It can give the user complete control over many aspects of their computing environment.

VBScript uses the Component Object Model to access elements of the environment within which it is running. For example, the FileSystemObject (FSO) is used to create, read, update and delete files. VBScript has been installed by default in every desktop release of Microsoft Windows since Windows 98. In Windows Server since Windows NT 4.0 Option Pack; and optionally with Windows CE (depending on the device it is installed on).

A VBScript script must be executed within a host environment, of which there are several provided with Microsoft Windows, including: Windows Script Host (WSH), Internet Explorer (IE), and Internet Information Services (IIS). Additionally, the VBScript hosting environment is embeddable in other programs, through technologies such as the Microsoft Script Control (msscript.ocx).

Postfix mail queue gets email stuck, the email should now be redirect to another recipient! Such a scenario can occur if no emails can be delivered to the original recipient address, for example when the mailbox space limit is reached, or the server responds with an error or there are the server is unreachable.

Here it can be helpful to temporarily send the email to another recipient. The tutorial shows the steps for delivering an e-mail remaining in the Postfix queue to an alternative recipient.

How to redirect queued mail to recipient

First, you look for the queue ID of the e-mail in the Postfix queue, which you want to redirect to another recipient address.

$ postqueue -p | grep 'john@example.org' -B 2

The parameter -B 2 outputs two additional lines before the parse.

The output can look similar to the following.

BCD2C3035D31!   37023 Thu Feb 17 08:59:55 suite102@mailings.daydeal.net
        (connect to 12.34.56.78[12.34.56.78]:25: Connection timed out)
                             john@example.org

Here an e-mail was sent to john@example.org which I want to deliver to a different address. The queue ID is BCD2C3035D31 which we need.

Alternatively, you can simply listing emails in the Postfix queues.

$ mailq

To prevent Postfix from trying to deliver the deffered email in the meantime, we set it to on hold with the -h option.

$ postsuper -h BCD2C3035D31
postsuper: BCD2C3035D31: placed on hold
postsuper: Placed on hold: 1 message

The e-mails are not deleted with on hold. The exclamation mark (!) indicates that the message is on hold.

Now you extract the e-mail and save it to a temporary file.

$ postcat -qbh BCD2C3035D31 > /tmp/email.eml

Now that the email is extracted, you can send it to a different recipient than the original.

$ sendmail -f john@example.org mike@domain.org < /tmp/email.eml

The e-mail will be sent from john@example.org to mike@domain.org.

Search the Postfix deffered queue for pending emails.

$ postqueue -vp

After the delivery to the new e-mail address has been confirmed, the e-mail can be removed from the Postfix queue.

$ postsuper -d BCD2C3035D31
postsuper: BCD2C3035D31: removed
postsuper: Deleted: 1 message

Delete the temporary /tmp/email.eml file.

$ rm -f /tmp/email.eml

Postfix helpful commands

Hint! To show Postfix queued e-mail contents.

$ postcat -vq BCD2C3035D31

Release mail that was put “on hold”.

$ postsuper -H BCD2C3035D31
postsuper: BCD2C3035D31: released from hold
postsuper: Released from hold: 1 message

Flush the queue, attempt to deliver all queued mail.

$ postqueue -f

To remove all e-mails in the Postfix deferred queue.

$ postsuper -d ALL deferred

Postfix Mail Queue Redirect Conclusion

As shown in this tutorial, it is possible to set e-mails from the Postfix mail queue to Hold, temporarily redirect them to other recipients, and remaining e-mails can also be removed from the queue for system hygiene.

Visual Basic Script Windows Logon with Message-Box