My Experience of Setting Up DKIM and SPF with Postfix and Ubuntu For Sending Email

I am developing a web application which needs to send email. The application is running on Ubuntu 12.04 64-bit and is using Postfix as the MTA, and therefore the web application is using Postfix to send outgoing emails.

To raise the chance of successful delivery of mail to the recipients, it is advised to setup DKIM and SPF for my environment.

Continue reading


How to Install Gitorious 2.4.x on Ubuntu 12.04

There are lots of tutorial flowing on the web regarding the installation instruction of Gitorious 2.4 on  Ubuntu, however the problem is (at the time of writing @ 2013-06-20):

  1. The instruction does not point out which version of Gitorious it is installing
  2. Some of them are just copying from other website.
  3. As of Gitorious 2.3/2.4 (I forgot), the ultrasphinx thing is deprecated and is switched to thinkingsphinx (yes, if you don’t know, than the guide you are reading is bad)
  4. The instructions you really always mentioned about Ubuntu 9/10/11.

Now I have spent hours on trying it on my configuration, and now I can tell you firmly what is the success factor: Continue reading

Ubuntu Seems Hangs After Reboot

Please refer to the post at this link:

In short:

  • After a power failure or whatever recent, the machine shutdown abruptly.
  • Upon reboot, it seems to the sysop that the machine can never come back.
  • You google a bit but find no resolution. Keyword: Ubuntu, GRUB.


  • The grub script has a default timeout = -1, which makes the menu does not have timeout.


  • For Ubuntu 12.04 and later, there is a option in /etc/default/grub to disable this type of timeout called GRUB_RECORDFAIL_TIMEOUT.
  • To solve this, set GRUB_RECORDFAIL_TIMEOUT  = 0 to disable the timeout, or a positive value for a delay in seconds. If set to -1, the menu will never timeout.
  • After changing the configuration, please run update-grub to make the change in effect.

External links: