On Wed, Dec 08, 2010 at 05:25:22PM +0000, Jonathan McDowell wrote:
On Wed, Dec 08, 2010 at 04:31:05PM +0000, Brett Parker wrote:
It's even better than that, because you're also not likely to have an external IP at all on 3G, vodafone 3G sticks, in my experience, tend to throw you in to a nat'd 10.0.0.0/24 address space.
Depends on the provider. When I had my Orange 3G USB dongle I got a real world, unfirewalled IP (dynamic though, so not useful as an SMTP endpoint). I believe there's an APN under 3 that gives this too.
I'd go for the VPN approach in all cases that didn't have a static IP at the destination end, whether there's NAT involved or not.
Surely many/most ISPs/hosting companies now provide authenticated SMTP on various ports other than the standard 25. Certainly all three that I use do so - that's Gradwell, Gandi and Tsohost. You just set up your mail (whether MUA or MTA) to use authenticated SMTP on the specified port and away you go. That works from anywhere, I just turn my netbook on and send away without worrying whether I'm on a hotel's WiFi, a 3G dongle (as at present0 or at home on my ADSL.