For quite a while my SpamAssassin installation for Windows won’t update anymore. It simply quit with some exit code 4. Unfortunately, SpamAssassin is running on this server for quite some time and often one simply forgets about systems that are up and running until they fail. Having a closer look at the error message it appeared that sa-update had some problems with some of the preconfigured channels.

C:\SpamAssassin>sa-update.exe -v --nogpg --channelfile UpdateChannels.txt
channel: no 'mirrors.khop-bl.sa.khopesh.com' record found, channel failed
channel: no 'mirrors.khop-general.sa.khopesh.com' record found, channel failed
channel: no 'mirrors.khop-sc-neighbors.sa.khopesh.com' record found, channel failed
Update failed, exiting with code 4

C:\SpamAssassin>if NOT EXIST .\share\3.003001\updates_spamassassin_org.cf EXIT /B 1

A look at the sa-update documentation reveals there might be a problem with downloading and extracting the updates.

An exit code of 4 or higher, indicates that errors occurred while attempting to download and extract updates.

As the sa-update.bat refers to a file called updatechannels.txt you probably find the failing channel entries there.

# see http://khopesh.com/wiki/Anti-spam#sa-update_channels
# for more information

updates.spamassassin.org
khop-bl.sa.khopesh.com
khop-general.sa.khopesh.com
khop-sc-neighbors.sa.khopesh.com

Digging a little bit deeper showed that the channels provided by Adam Katz at http://www.khopesh.com/ became unmaintained. Therefore, the easiest way to get rid of the failures is to remove the entries from the file for good. Eventually, this will leave you with only the official channel at updates.spamassasin.org.