Claim notices in acquisitions should use the message_queue table. By using the message_queue table or a similar table it would be possible to find out, when a notice was sent out to a vendor, how it looked like, how the text was formatted and which informaton it contained.
Sent claim notices are written into the action_logs table now. (bug 5347) I am marking this resolved fixed, as we currently use the message_queue only for messages to borrowers and the action_logs table contains all important information now.