Due to the different corporate policies it is not possible to use IMAP integration as it is now. Introducing more configuration options (that normally exist in e-mail clients) would allow tailoring mail integration to comply with policies, or just make it more usable for mobile use when data traffic is limited.
Two options that would be essential in my case are:
1. IMAP checking interval in minutes - to adjust how frequently Nimble checks IMAP account
2. Option not to download attachments - in our case policy is that attachments cannot be held on servers outside our security perimeter