[Evolution] Evolution's http cache

[Brian Mury <b mury ieee org>]

I seem to be accumulating a large number of files in
~/.evolution/cache/http. I'm up to 95 MB. Most of these (at least from
the small sample I've looked at so far) are from emails that have been
deleted and purged, and they go back over a year.

Is this cache supposed to be cleared automatically, and if not, is there
a way to clear it on command, other than just deleting the files? Is it
safe to just delete the files?