Postfix question

[Mark Johanson]

Just using Postfix for localhost mail. Not getting or sending
mail from/to anywhere. Can the SMTP (port 25) be shut off in a
config file some where or is it just on and nothing I can do
about it?

Just curious as I use my laptop both at home and at work. With
how anal work is starting to get about scanning the network I
would rather not have that show up in a scan. I generally know
before hand that a scan is coming so I have just taken it off
the network during said scans.