I would like to have MailScanner on a Ubuntu Dapper server for internal server. There are many receipts including a good one at wiki. Anyway, I add a few modification to make it more easier to debug. Follow me.

My friend asked me to verify suspension of web hosting services which the domain name server has been changed to other hosting service. He just has a long file with a domain per line. The trick is to query NS record of each given domain to see whether it is his name server or not. It is very easy to do so for a domain but it is not funny for thousand domains.

sudo is a must to have in all Unix host to prevent wide-spread of root account. It also has built-in security checking by time. However, sometimes this feature might annoy sudo to stop working after adjusting date/time back from the future.

sudo: timestamp too far in the future: Aug  9 18:31:44 2007

To solve this problem, I have a clue.

Sometimes you may want to classify web traffic per user, not IP-based classification, in Squid. Squid supports this mechanism via external authentication plugin. The most common one is NCSA authentication but a flexible one is PAM since it is possible to use LDAP backend as well as unsecured passwd and shadow.

Most offices have internet access especially for managers and employees to read and compose e-mails with customers. Anyway, everything has their bad side so most employees will try to access other things consuming more traffics, e.g., music videos, video streaming, songs and many more. As a result, e-mail applications may slow down. Since most of them will also have proxy to save valuable bandwidth and a popular one is Squid, [SquidGuard][] is able to help controlling internet usage for unimportant purposes.

Even though Mplayer is able to play RMVB by binary codec, sometimes it may not work as expect due to something weird as follow.

mplayer: symbol lookup error: /share/apps/codecs/drvc.so: undefined symbol: pthread_mutexattr_init

Fortunately, it has a workaround for this issue.