[The Thunderbird 2 version of this can be found here.]
Every once in a while, someone on news.mozilla.org will enquire about receiving an error message “A News (NNTP) error occurred: xpat not supported“, when trying to search newsgroups on news.mozilla.org; so I thought I’d post my ‘stock’ answer. 🙂
News.mozilla.org is hosted by Giganews, who’s servers do not support XPAT commands.
To quote one of the Giganews support personnel:
“The XPAT command attempts to search through our entire spool of over 700 million articles, to match on a specific keyword, that is often found only in a handful of newsgroups. The command puts enough of a load on our servers, that several people using this at one time can affect the performance that all of our customers receive.”
Disabling XPAT support is not an uncommon thing. When using the “Search Messages” function in Mozilla Thunderbird [Edit–>Find–>Search Messages], the XPAT command is used to search that news server. The workaround for this is to make Thunderbird search messages locally. There are a couple of ways to do that:
1. Use the search bar [View–>Toolbars–>Search Bar].
2. Before opening the search window, you can switch to offline mode [File–>Offline–>Work Offline]. There’s also an offline toggle icon in the bottom left of the Thunderbird window.