Thanks.
Some properties are correctly returned but Robert asked for the list of visible messages and it fails :
tell application "Mail"
set frontMsgVwr to (some message viewer whose index is 1)
log frontMsgVwr --> (*message viewer id 34*)
tell frontMsgVwr
set vCol to visible columns
log result --> (*message status column, flags column, attachments column, from column, subject column, to column, date received column, mailbox column*)
set oBox to outbox
log result --> (*outbox*) ???
set pView to preview pane is visible
log result --> (*false*)
set selMbox to selected mailboxes -- Errors if Smart Mailbox is selected
log result --> (*mailbox INBOX of account iCloud*)
set visibleMessages to visible messages
--> error "Erreur dans Mail : Le gestionnaire AppleEvent a échoué." number -10000
end tell
end tell
So, given the fact that asking for this property fails it's logical that asking for the entire set fails too.
Maybe grabbing visible messages fail for years. I never used this piece of code before reading Robert's question.
Yvan KOENIG running Yosemite 10.10.4 (VALLAURIS, France) mercredi 8 juillet 2015 18:43:42