Sometimes headers from Outlook missing

A user of my application Mail Archiver X wants to archive emails from Outlook. However, only a small number of emails are being archived. The app can log all AppleScripts and the result. When getting the headers some of the emails don’t have one - at all.

I have AppleScripts to get the mailboxes and for each mailbox the number of emails in the mailbox.


property Mailbox0 : "mailbox1"
property Mailbox1 : "mailbox2"
property Mailbox2 : "mailbox3"
property Mailbox3 : "account1"
property currentMessageStr : "40"
with timeout of 10000 seconds
set currentMessage to currentMessageStr as integer
tell application "/Applications/Microsoft"
set theFolder to mail folder Mailbox0 of mail folder Mailbox1 of mail folder Mailbox2 of exchange account Mailbox3
return headers of message currentMessage of theFolder
end tell
end timeout

I made the guy a direct AppleScript but the user is a lawyer and security conscious. He didn’t want to run the AppleScript.

Any ideas what could cause the missing headers?

macOS 14.1