Hi - I haven't tried this on my DS207+, yet (I might, when I have time later today) but I have set up local email clients to use the gmail smtp server. According to gmail's help here: http://mail.google.com/support/bin/answ ... swer=76150
the smtp server is gmail.smtp.com. If you haven't already done so, you might try setting up a local client on your computer to make sure that works from your location. Have you already tried your ISP's smtp server from the DS207+ to make sure the setting on the DS207+, firewall, etc. are working (so that you can rule out the problem being unrelated to gmail)?
I'll get back to you later if I get a chance to try this (probably tonight after work).