Category: Internet Stuff

Email Server

Ryanexim, greylisting, spamassassin

I’m not a big fan of using greylisting to cut down on email spam, since it tends to big a big pain in the ass when I run into it running on other email servers. On the other hand the amount of incomming spam has risen to a level where I decided it’s time to really do something about it (not that Spamassassin was doing a bad job, but it shouldn’t have to go through hundreds of mails each day to sort out the 15-20 real mails).

So I did a quick google what packages were recommended for greylisting with exim, and ended up using “greylistd” which came with a nice example config for exim. I went through the config and loosened up the settings a bit. And after letting it run for 2 days, the stats say that a bit over 96% of incoming mail was never retried (e.g. either spam, or a crappy MTA sending me mail).

Next thing I’m having a look at is SPF. I’ve got it up and running, but it only throws warnings to the log right now, doesn’t block anything (same goes for messed up DNS entries of servers sending me mail).

Something positive I noted was that the number of MTA servers supporting TLS connections seems to be rising. Server <-> Server encryption of data is a good thing. Having users view and send mail via secure HTTPS/SSL/TLS cconnections is pretty useless if the mails gets forwarded to the destination in plaintext.

Photoshop Express

Ryanadobe, online, Phodoshop

Photoshop Express seems to have finally gone online https://www.photoshop.com/express/landing.html An online (web application) version of Photoshop. Of course with only a basic variaty of functions, but still plenty useful.
After registering you get 2GB of space for uploading/editing pictures. Uploaded pictures can either be defined private, or can be public and displayed in a gallery. The only technical requirements are a current browser with flash player 9 installed.

Google Calendar

Ryan

After a friend told me about how useful google calendar is (I had heard of it before, just never looked at it), I finally went and registered at google to have a look myself. For a web application the gui is pretty good. What I liked most about it, is that I can easily synchronize the entries in google calendar with my calendars in thunderbird or my cell phone. For my cell phone I use MyPhoneExplorer (already had that installed, I use it to write SMS via a bluetooth connection to my computer). For thunderbird I use to addons. The first is a calendar addon called Lightning since thunderbird has no calendar out-of-the-box. The second is an addon written to sync between google calendar and thunderbird called Provider.

Everything was pretty straight-forward to setup, took me less than half an hour to find information, get everything installed and running smoothly.

Links:
Google Calendar http://www.google.com/calendar/
Provider https://addons.mozilla.org/de/thunderbird/addon/4631
Lightning https://addons.mozilla.org/de/thunderbird/addon/2313
MyPhoneExplorer http://www.fjsoft.at/de/downloads.php

Streaming a webcam over narrow bandwidth

Ryan

Just some random lego that I whipped up this week. Wanted to stream a webcam into the internet using a minimum of upstream bandwidth (that’s the reason I stream it to a server with a fast connection, where it is provided to clients). I probably could have used a higher fps oder quality, but I wanted to find a solution that didn’t require any additional software to be installed clientside (and this solution works over proxies).

Client side: grab video output from /dev/video0, put a timestamp in the picture, and shove it to the IP 10.11.12.13 (not really).

vlc v4l:/dev/video0:size=320×240 –sub-fps 3.0000 –v4l-fps 3.0000 –sout-transcode-fps 3.0000 \
–sout “#transcode{vcodec=WMV1,vb=60,scale=1,sfilter=time,fps=3}:\
duplicate{dst=display,dst=std{access=rtp,mux=ts,dst=10.11.12.13:1234}}” \
–noaudio –no-sout-audio –time-format %Y-%m-%d,%H:%M:%S \
–time-position 10 –time-color 16777215 –time-size 12 &

Server side : grab the stream from the cam (no options needed since we sent it to the default port 1234) and provide it as mms:// on port 8080 (I choose mms:// since all windows computers have the windows media player)

vlc udp: –sout ‘#standard{access=mmsh,mux=asfh,dst=10.11.12.13:8080}’