central amavis machine for in and outbound

[Tobias Hachmer]

Hello

does it make sense or does anyone got such an environment productive:

- one or two MX for several domains(seperate machines)
- one or two MTAs only for outbound mail purpose(seperate machines)
- one(or maybe two) central amavis machine(powerful) the 2-4 e.g. 
postfix machines uses for pre-queue-filtering

Does such a scenario make sense?
Are there any pros or cons?

Please let me take a part of your experiences and sentiments...

Regards,

Tobias