I have found out, to my annoyance, that spell checking a message in Horde causes the message to be lost. Both instances have been idential - Long messages (typically!) with more than 3 corrections / queries. After accepting / rejecting the first 3 corrections, I click the Next button to show the next 3. Both times, I get, "Internet Explorer Cant Display The Page". There is no back button, and despite all attempts, recovery of the message is not possible.
I would use Netscape which is much more stable, but the whole point of Webmail is that I am using someone elses PC and usually they have IE on it (they might all learn someday...)
Its such a nuisance that its making it hardly worthwhile to use webmail.
Reported to Zen, but just the usual automated response...