Find Out My Linux Distribution Name and Version

cat /proc/version

nslookup - query all reconds for specified domain name

cmd
nslookup
set type=any
youdomainname

you will get the list of all records

debian squeeze backports

official site (link) statement

1) For squeeze add this line

deb http://YOURMIRROR.debian.org/debian-backports squeeze-backports(-sloppy) main

BUT do:
edit /etc/apt/source.list

add
deb http://YOURMIRROR.debian.org/debian-backports squeeze-backports-sloppy main
without "(.....)"

P.S.
check this link - http://backports-master.debian.org/Mirrors/ to find the nearest mirror.
Click on the link "debian-backports" in "ftp" column
You will get the page with content.
Some servers will have only wheezy backports.
Most of them will have folder named "squeeze-backports-sloppy" under dist folder.
Not squeeze-backports(-sloppy).

Good luck.

NIS domain name not set - NIS lookups disabled

NIS domain name not set - NIS lookups disabled

#postconf | grep nis

output:
alias_maps = hash:/etc/aliases nis:mail.aliases
or
alias_maps = hash:/etc/mail/aliases nis:mail.aliases


disable NIS lookups (as root):
# postconf -e alias_maps=hash:/etc/aliases
or
# postconf -e alias_maps=hash:/etc/mail/aliases

postfix queu

check queu - mailq
delete all messages in queu - postsuper -d ALL

install debian package

 dpkg -i PackageName

debian - list install packages

dpkg --get-selections | grep roundcube