Postfix configure anti spam with blacklist

Postfix is free and powerful MTA. You can easily configure Postfix to block spam. You need to add following directives to /etc/postfix/main.cf file:

disable_vrfy_command = yes : Disable the SMTP VRFY command. This stops some techniques used to harvest email addresses.

smtpd_delay_reject = yes : It allows Postfix to log recipient address information when rejecting a client name/address or sender address, so that it is possible to find out whose mail is being rejected.

smtpd_helo_requi
red = yes
 : Require that a remote SMTP client introduces itself at the beginning of an SMTP session with the HELO or EHLO command. Many spam bot ignores HELO/EHLO command and you save yourself from spam. Following lines further restrictions on HELO command:
smtpd_helo_restrictions = permit_mynetworks,
reject_non_fqdn_hostname, Reject email if remote hostname is not in fully-qualified domain form. Usually bots sending email don’t have FQDN names.
reject_invalid_hostname, Reject all bots sending email from computers connected via DSL/ADSL computers. They don’t have valid internet hostname.
permit Continue reading Postfix configure anti spam with blacklist

Setting Up Postfix As Buckup MX

In this tutorial I will show how you can set up a Postfix mailserver as a backup mail exchanger for a domain so that it accepts mails for this domain in case the primary mail exchanger is down or unreachable, and passes the mails on to the primary MX once that one is up again.

I do not issue any guarantee that this will work for you! Continue reading Setting Up Postfix As Buckup MX

vCenter Converter Standalone 5 – Increasing the cloning performance

There have been many complaints about transfer rate degradation in Converter 5.0.

Converter uses NFC (a proprietary VMware protocol) for cloning to managed destination. Security has been enhanced in Converter 5.0 by encrypting the data transfer. Unfortunately this has caused a more severe performance degradation than expected. Switching off SSL encryption is a . . . → Read More: vCenter Converter Standalone 5 – Increasing the cloning performance

Installing Papercut NG on Debian 6

PaperCut’s print management delivers real bottom-line savings for organizations of all sizes. Our software is scalable and customizable to your specific business needs. Implementation ranges from silently tracking employee usage by individual, office or department, to explicit reporting of usage costs, budgeting, and environmental impacts. Rest easy knowing your organization’s printing is being monitored and under control.

Key features at a glance:

  • Encourage responsible use of company resources.
  • Silently track printing and associated costs by individual user, office or department.
  • Printing can be monitored and reported or charged back on a per-document, per-user, per-client or per-department basis.
  • Actively manage the print process with filters, routing and redirection.
  • Stay on top with regular print monitoring reports to analyze and audit printer usage.
  • Educate workers, and create an environmentally aware workplace.
  • Simple installation and easy to use. You can begin tracking immediately by installing on your existing servers.
  • Suitable for Windows, Mac, Linux and Novell, making PaperCut the most flexible and integrated print monitor solution available.
  • Take the tour, and Download PaperCut NG.

Continue reading Installing Papercut NG on Debian 6

how to add a static route to vmware esxi server

ESX console “unsupported” trick to add static route to a ESXi host.

How to add a static route to ESXi machine:

Login to local console Hit Alt+F1 Type (there is no feedback): unsupported Console will show Password prompt Enter root password Use esxcfg-route command to manipulate routing talbe entries e.g. #> esxcfg-route -a . . . → Read More: how to add a static route to vmware esxi server

How to: Upgrade to vSphere 5

On July 12th, VMware announced the release of vSphere 5.

With the release comes the challenge to upgrade your existing installation.

However, there are a few caveats:

vSphere 5 is the first version which comes in a ESXi version ONLY! ESXi 5 is available in an embedded or installable version. If you’re running ESX . . . → Read More: How to: Upgrade to vSphere 5

vSphere 5 Auto-deploy in 20 steps

One of the new features of VMware vSphere is booting the ESXi hosts from PXE. This feature is called Auto-Deploy and gives you the ability to use stateless ESXi servers.

Below is a step-by-step guide to get you started. It assumes you use the vCenter Virtual Appliance. of course auto deploy also works with . . . → Read More: vSphere 5 Auto-deploy in 20 steps

Setup Mikrotik OpenVPN Server using CAcert with Linux Client

Creating Mikrotik OpenVPN Server Certificates

OpenVPN works with SSL certificates. You can either use http://cacert.org to issue these or use the easy-rsa scripts, that come with most OpenVPN distributions. On RouterOS, all you have to do is to upload them via ftp (ca certificate and router certificate and private key) and import them with . . . → Read More: Setup Mikrotik OpenVPN Server using CAcert with Linux Client

Setup NTP time server in Windows 2008 R2

Step 1: Net time /setsntp: W32tm /config /syncfromflags:manual /manualpeerlist: W32tm /config /reliable:yes W32tm /config /update W32tm /resync Pause Exit

Step 2: [HKEY_LOCAL_MACHINE\SYSTEM

\CurrentControlSet\Services\W32Time\Config] “AnnounceFlags”=dword:00000005 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters] “Type”=”NTP” [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer] “Enabled”=dword:00000001

Step 3: Net stop w32time Net start w32time Net time Pause Exit

Command in login script: Net Time \\<LocalTimeServer’sName /Set /Yes

Clipboard Copy and Paste option is disabled in vSphere Client 4.1

Symptoms

  • Cannot copy and paste from the virtual machine remote console to the system in which the vSphere client is installed
  • The Copy and Paste options are disabled in vSphere 4.1
Note: This functionality was enabled by default in earlier releases of vSphere.

Continue reading Clipboard Copy and Paste option is disabled in vSphere Client 4.1