Stretch => Buster: AppArmor

[Jesper Dybdal <jd-debian-user@dybdal.dk>]

At some point I will have to upgrade from Stretch to Buster, and I am 
beginning to consider which problems I might run into.  So I have some 
more or less stupid questions that I will post in separate threads - 
this is the first.

Buster enables AppArmor by default.  I know just about nothing at all 
about AppArmor.  Does it constitute a risk that some of my existing 
programs will not work?

For instance, my postfix installation (which is by far the most 
important application I run) uses a few non-standard tcp ports to 
comunicate with helper services and to receive mail submissions - is 
there a risk that AppArmor will block that?

Is there a simple way to disable AppArmor completely until I've had time 
to figure out what to do with it long-term?

Thanks,
Jesper

--
Jesper Dybdal
https://www.dybdal.dk