Just as reference for anyone else who think of undertaking this task - DON’T unless you have multiple backups.
I’m not sure where it all went wrong, but I used emClient for moving emails between Outlook and iCloud and then back again. At some point ALL the emails had ALL their timestamps overwritten with the date and time of move, and ALL the headers blanked out. Thereby screwing up my entire mailbox from a date/time usability perspective.
Well not exactly, because I had a backup of a great deal of older emails in a PST due to running out of space on Outlook, but for the newer ones …
Well let’s just say that I’m heavily using AI to reconstruct them from the data contained within the addresses, subject, body and any attachments.
As a 40-year veteran of IT, and having multiple backups for everything for many years, it’s a stark reminder of how easy it is to lose focus, and assume that technology can handle a basic move of an email, without deciding or checking that the date times have not been “re-assessed”!
I’m not sure this was the fault of emClient, and some subsequent tests showed moving works without an issue on individual emails, but surely some minimal checks that the email has arrived in the same condition before obliterating the old one would be a professional approach to the job?!