Ubuntu - E: Package has No installation candidate

If you are facing this error on ubuntu, Run following command.

# sudo apt-get update

Postfix - master dead but pid file exists

Stop and start postfix. Do not restart, use individual commands for stop & start.

If you are still facing the problem
Remove /var/spool/postfix/pid/master.pid and /var/lock/subsys/postfix
Stop and start postfix

If you are still facing the problem, Check what is running on port 25

# netstat -lnp | grep :25

Kill the process and start postfix again.

ubuntu - Compiler error - msgfmt command not found

Install following package

# sudo apt-get install gettext

or

use '-i' while installing package from source code.
make -i install