Best Practice for this?

Hi,

i am not unexperienced with UTM`s Functions. But i havent done SMTP/POP3 Configurations yet.

So here is my question:

We are setting up a UTM 120 with WLAN Access. Users can buy Vouchers and use WLAN via the firewall.

I guess there will be some users that want to use mail programs using smtp and pop / imap ports.

how is that done secure and simple? just opening the ports or using some kind of smtp or pop proxy?

thank you for your info