mail spam rabl.nuclearelephant.com is dead

Today some mails did not reached my inbox and were blocked through my postfix spam filter rabl.nuclearelephant.com.
It seems that this rbl is not available since today.

See this info on sourceforge forum page.

Any legacy services that might have been hosted on nuclearelephant.com have been discontinued, in particular rabl.nuclearelephant.com

Solution:

simply remove from your postfix main.cf:
reject_rbl_client rabl.nuclearelephant.com

Ubuntu Intrepid, Firefox and Flash

After upgrade from Ubuntu hardy to intrepid last year, i had nearly every day problems playing embedded flash on websites.
I hate it, but it was not my first priority to solve and a Firefox restart solved it every time.

Suddenly i found this simple solution: http://ubuntuforums.org/showthread.php?t=967049

apt-get remove flashplugin-nonfree
apt-get install ubuntu-restricted-extras


Works fine now. I can see all content from slideshare and youtube.

get usb headset working with Amarok or Xine

It is a little bit tricky to get a USB headset working with Ubuntu and Amorak.

(i never use KDE, but this tool is my current favorite music player under Ubuntu. Things changes, may be there
is a another favorite player anytime. For now, Amarok 1.4.10 rocks! I donated a small amount of money for the guys of Amarok -> good job !!!).

My current Amarok version from Ubuntu Hardy or Intrepid distributions (XFCE desktop) identifies on-board soundcard only.

But i want to listen to music from my USB headset!.
So a small little manual configuration, let Amorak play music out of my USB headset:
First you need to identify the sound card identifier, i took alsactl, but other ways are possible of course:
sudo alsactl names

This creates /etc/asound.names and there you can find your assigned device, for example:
alsactl24 {
name 'plughw:1,0'
comment 'Physical Device With Conversions - USB Audio (Duplex)'
}


Now open Amarok and configure
Settings / Amarok / Engine
– Sound System: xine Engine
– Output plugin: alsa
– Mono and Stereo: plughw:1,0
– 4 Channels and 6 Channels: leave empty (i left it untouched).

or look on this screenshot:

OK

Now you can here sound from your USB headsets!

disable system beep under Ubuntu completely

If you use XFCE and have not System/Preferences, but want to disable system beep completely:
echo "blacklist pcspkr" | sudo tee -a /etc/modprobe.d/blacklist

With next reboot cannot here the annoying system-beep or if you don’t want reboot, run:
sudo modprobe -r pcspkr.

Congratulations to Ubuntu 8.10 Intrepid

The time is now!

Yesterday was a great day.
I’ve got my new mainboard Gigabyte GA-EP45-DS4 and tried to install Ubuntu/Hardy.
Unfortunately, the boot CD hang with during startup (at the USB check time) and the only thing i got, was the busybox.
After updating the BIOS to the latest F9 version, it was time to look at the new Ubuntu Release.

Success! They released yesterday the latest Ubuntu Release 8.10 (Intrepid).

Installation on the ICH10 chipset board EP45-DS45 works like a charm without any issue !!!

Good work Ubuntu Team!

As ever, i use the Xubuntu AMD64 Alternate Image, because XFCE works much faster, than Gnome or KDE.
As every download from all mirrors were slow, i used the torrent download to get maximum download speed!

show harddisk and cpu temperature with Ubuntu

To configure a Ubuntu (Intrepid) to show sensor data in desktop panel, simply install sensors.
With my new mainboard and ICH10 chiptset, i haven’t got access to hard disk and cpu temperatures,
i only got
“Sensors type ACPI zones”

apt-get install xfce4-sensors-plugin sensord i2c-tools
apt-get install xsensors

After that run as root:

sudo sensors-detect
It added “coretemp” to /etc/modules.

Additionally you need to let sensors plugin get access to hddtemp to read harddisk temperatures as user:
chmod u+s /usr/sbin/hddtemp

Then you need reboot your system.

Voila! CPU and hard disk temperatures are displayed.
Very nice is, that i can set Min/Max for the color display.

The ACPI thing didn’t work, but that’s okay for the moment.

ubuntu hardy apt-get upgrade Hash Sum mismatch

today on one of my server box occurde a “Hash Sum mismatch”.
why suddenly ?

apt-get upgrade

Fetched 1B in 0s (4B/s)
W: Failed to fetch http://de.archive.ubuntu.com/ubuntu/dists/hardy-security/multiverse/binary-amd64/Packages.bz2  Hash Sum mismatch

*Update:*
one day later, doing nothing this error message is gone. i suppose a problem on the used mirror.

install postgrey for postfix on Ubuntu

Greylisting is yet another way for preventing your mailbox getting full of spam. A famous spam fighter software is spamassassin which filter emails. Greylisting won’t replace such softwares but it will behave as a powerful proactive barrier which will reduce the amount of spam getting through your mail server.

Greylisting is a great way for fighting spams, the basic idea out of it is that spammers mail servers are not respecting RFC standards specifications which basically says that when an email could not be delivered, the mail server should try again later on. By sending so many emails, spammers can’t afford to spend to much resources on resending emails when they could not be delivered, so if the email could not be delivered in the first place, they won’t send it back to you.

From this ideas, greylisting simply reject any untrusted mail domain by giving a 450 response code, which means “I can’t deal with your request now, please try again later”.
As spam mail server are not usually RFC compliant, they won’t try back and therefore you won’t get the spam.

Postgrey is a postfix policy server implementing greylisting.
It is really easy to integrate to postfix and is really effective.

step 1: install postgrey

apt-get install postgrey libnet-rblclient-perl libparse-syslog-perl libio-socket-ssl-perl

i got a warning during installation, but that can be ignored:
Warning: The home dir /var/lib/postgrey you specified can't be accessed: No such file or directory

step 2: add check_policy_service inet:127.0.0.1:60000 to /etc/postfix/main.cf

for example:
smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination, check_policy_service unix:private/policy, check_policy_service inet:127.0.0.1:60000

step 3: reload postfix configuration

/etc/init.d/postfix reload

step 4: send a test mail and verify your /var/log/mail.log

first entry

Jul 19 18:13:58 MYHOST postgrey[10713]: action=greylist, reason=new, client_name=CLIENT_HOST, client_address=CLIENT_ADDRESS, sender=SENDER_EMAIL, recipient=RECIPIENT_EMAIL

second entry (some minutes later, depends on sender’s MTA)

Jul 19 18:20:20 MYHOST postgrey[10713]: action=pass, reason=triplet found, delay=382, client_name=CLIENT_HOST, client_address=CLIENT_ADDRESS, sender=SENDER_EMAIL, recipient=RECIPIENT_EMAIL

(optional) exclude some recipients from whitelisting

edit /etc/postgrey/whitelist_recipient and add e.g. YOURDOMAIN.COM to exclude this address from greylisting processing.

# postgrey whitelist for mail recipients
# --------------------------------------
# put this file in /etc/postgrey or specify its path
# with --whitelist-recipients=xxx

postmaster@
abuse@
YOURDOMAIN.COM

(optional) postgrey report

to get a postgrey report, simple run this command:

cat /var/log/mail.log | postgreyreport --nosingle_line --check_sender=mx,a --show_tries --separate_by_subnet="--------------------\n"

Reduce spam and enjoy postgrey!

sensors xfce4 plugin in ubuntu hardy

to monitor local sensors, like cpu or temperature, simple install a xfce4-sensors-plugin:

apt-get install xfce4-sensors-plugin xsensors lm-sensors sensord hddtemp

see also:

• http://packages.ubuntu.com/de/feisty/xfce4-sensors-plugin