Apparently, Mail.app _may_ crash after the 10.5.6 update if it wasn't updated properly. Apple offers the update separately here: http://support.apple.com/downloads/Mail_Update
Must say I haven't heard about the problem on anyone's computer so far.
The text for the update reads:
"About Mail Update
This update addresses stability issues with Mail.
After updating to Mac OS X 10.5.6, Mail may unexpectedly quit. This can be caused by using a copy of Mail that wasn't updated properly (you may need to install the Mail Update)."
Must say I haven't heard about the problem on anyone's computer so far.
The text for the update reads:
"About Mail Update
This update addresses stability issues with Mail.
After updating to Mac OS X 10.5.6, Mail may unexpectedly quit. This can be caused by using a copy of Mail that wasn't updated properly (you may need to install the Mail Update)."