Why are there both periodic .txt.and .txt.gz files in the archive?

The .txt.gz files are an anachronism from the days when the bit of bandwidth saved by delivering a compressed version was important. These days, the bandwidth savings is unimportant and is probably offset by the redundant storage and processing for the .txt.gz files.

To stop keeping both the .txt and .txt.gz versions do the following:

• Remove the nightly_gzip job from Mailman's crontab.
• Ensure the Defaults.py/mm_cfg.py setting for GZIP_ARCHIVE_TXT_FILES is No.
• Remove all the archives/private/*/*.txt.gz files.

There will be an issue in that there will still be links on the archive Table of Contents pages to the .txt.gz files. For an active list, this will automatically be corrected the next time the archive is updated, but to do this sooner and for inactive lists, see this withlist script.