You can do both.
Have a email filter, and use Session-Timeout.
Id venture to suggest 15mins is not long enough. Maybe 2 hours
-there isn't much else thay can do is there?
Here's my email only filter - note it allows connections
to any host on the class C / ports 25 and 110 (smtp / pop)
You can easily modify it to allow specific hosts using /32 mask
add filter email.in
set filter email.in 1 permit 0.0.0.0/0 0.0.0.0/0 udp dst eq 53
set filter email.in 2 permit 0.0.0.0/0 0.0.0.0/0 udp src eq 53
set filter email.in 3 permit 0.0.0.0/0 194.74.214.0/24 tcp dst eq 110
set filter email.in 4 permit 0.0.0.0/0 194.74.214.0/24 tcp src eq 110 estab
set filter email.in 5 permit 0.0.0.0/0 194.74.214.0/24 udp dst eq 110
set filter email.in 6 permit 194.74.214.0/24 0.0.0.0/0 udp src eq 110 estab
set filter email.in 7 permit 0.0.0.0/0 194.74.214.0/24 tcp dst eq 25
set filter email.in 8 permit 0.0.0.0/0 194.74.214.0/24 tcp src eq 25 estab
set filter email.in 9 permit 0.0.0.0/0 194.74.214.0/24 udp dst eq 25
set filter email.in 10 permit 194.74.214.0/24 0.0.0.0/0 udp src eq 25 estab
add filter email.out
set filter email.out 1 permit 0.0.0.0/0 0.0.0.0/0 udp dst eq 53
set filter email.out 2 permit 0.0.0.0/0 0.0.0.0/0 udp src eq 53
set filter email.out 3 permit 194.74.214.0/24 0.0.0.0/0 tcp src eq 110 estab
set filter email.out 4 permit 194.74.214.0/24 0.0.0.0/0 tcp dst eq 110
set filter email.out 5 permit 0.0.0.0/0 194.74.214.0/24 udp src eq 110 estab
set filter email.out 6 permit 194.74.214.0/24 0.0.0.0/0 udp dst eq 110
set filter email.out 7 permit 194.74.214.0/24 0.0.0.0/0 tcp src eq 25 estab
set filter email.out 8 permit 194.74.214.0/24 0.0.0.0/0 tcp dst eq 25
set filter email.out 9 permit 0.0.0.0/0 194.74.214.0/24 udp src eq 25 estab
set filter email.out 10 permit 194.74.214.0/24 0.0.0.0/0 udp dst eq 25
Framed-Filter-Id = "email",
Hope this helps.
Paul Gregg
-- The Internet Business Ltd, Holywood House, Innis Court, Holywood, BT18 9HF pgregg@tibus.net http://www.tibus.net/ Phone: +44 (0)1232-424190 Fax: +44 (0)1232-424709 Eight out of every five people are math illiterates.