recover IMAP emails from offline ipad

you could forward them to yourself and when in the outbox you go online once more

How did you accidently lose a chunk of emails in Outlook? Did you lose your pst, or ost file? If the files were not deleted from Outlook and off the server, they are still on the server. Unfortunately, the iPad does not store a copy of the pst/ost file, so that recovery is not an option.

Assuming you have a PC you can try TouchCopy: https://www.wideanglesoftware.com/touchcopy/

imap maintains a common image of the emails on the server. All imap clients should reflect the same view.

I'd logon to the server via a web browser and see what is on the server.

you could delete your imap account on the ipad the redefine it. All emails will be downloaded again. ( Assuming they are still on the server. That's why you check before deleting the account. )

From what you describe at this point, I would have to say your best alternative is as deggie has suggested, a 3rd party software that you may be able to recover the mail from the iPad. You are correct in not connecting it to the internet, as you would immediately lose the information. While it also may not recover all of the mail, if you have Outlook configured correctly, you should have an auto-archive file generated. It depends on how you have configured it, but it is generally a 7-14 day cycle that would have some of those emails in the archive file. Sort of an auto-backup. If the 3rd party software suggestion that deggie made does not work, this would probably be the only other alternative you have. While it may not get everything, it could recover some. This would also be the catalyst to get you to ensure you have your auto-archive set up as well.

Is there no daily backup of the computer/server that contains the mail? That may also contain a copy of your pst/ost file that may help in recovering some of the mail.

mail providers backup their data in case of their server going belly up so you can try to contact the mail provider

or you can try to google programs which can extract information from a itunes ios backup and see if you get get some mail data out that way

Check Wide Angle Software, a program called TouchCopy. It works on both Windows and Mac computers. There is a cost, however it seems this material is important enough that you would be willing to pay. Although it is not that expensive. I've used it for many things so far, and I can say it works quite well. I'm not sure what kind of time you are looking at here to try and recover 1000+ emails, but whatever.