[postfix-users] Difference mydestination and virtual_alias_domains etc.

[Dennis]

Hi,

according to the book of Postfix and from my understanding the purpose 
of virtual_alias_domains is exactly the same
like mydestination which is to be the final destination for the domain 
names specified.

The difference is that virtual_alias_domains doesn`t need to have a 
correlation to the host machine, right?
But what does that mean in practice?
Wouldn`t it be the same if i decide to set all domain names postifx is 
the final destination for, in mydestination instead of 
virtual_alias_domains?

I dont exactly understand the difference and whats even more confusing 
for me is the difference between virtual_alias_domains & 
virtual_mailbox_domains.
Maybe some Zenmaster in Postfix could enlighten me and sorry about my 
stupid questions, i am still a Postfix fool but at least i try. xD

Regards

Dennis