I use my email from my phone and my computer via IMAP. I want to set something up so that if I delete a message via my phone, my computer will still keep the message locally.
For example, assume I leave my computer on, with a synchronize interval of 5 minutes. I want to be able to send something from my phone, wait 5 minutes to be sure my computer has downloaded the item from the Sent folder, then delete it from the IMAP sent folder via my phone, but have the computer at home keep it's copy.
Is this possible with any readily available email clients out there? I have Thunderbird and Outlook at the moment, but would be willing to learn a new interface for this feature. How can I accomplish this?
In response to RedGrittyBrick's comment:
The purpose is to maintain a complete, automatic (offline) backup of every message to pass through the account. For various reasons, certain messages may not remain on the IMAP server, but do need to be kept in offline storage.