[Exim] Exim vs Micro$lop Exchange with smtp priority

Greetings,

I'm not entirely aware of any mechanisms .... but would it be possible for
exim to run its queue's delivery retries in a similar fashion to Exchanges?
i.e. a message flagged as high priority gets retried at a higher frequency
rate if not delivered.

I'm getting some stick from the exchange admins about exchange delivering
mail faster than exim and therefore want to bypass the AV scanner as well.

Secondly, is this an RFC compliance issue ?

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Thank-you for your time.

John Ward