On Wed, Dec 08, 2010 at 05:50:42PM +0000, Chris G wrote:
On Wed, Dec 08, 2010 at 05:25:22PM +0000, Jonathan McDowell wrote:
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.
The originally query was about inbound SMTP when the primary ADSL link was down.
For outbound SMTP relaying through a smarthost on 587 (submission) using STARTTLS to encrypt is definitely the way to go; this is the way my laptop is configured meaning it doesn't matter which network I'm on.
J.