I want to send one particular email from my laptop to my dreamhost email address, using my laptop's smtp client, bypassing my ISP's smtp server and connecting direct to DreamHost's smtp server. (It's for a phone-home script in the event of the laptop being "mislaid", so I can't use my ISP's server since the thief likely will be using a different ISP.)
Dreamhost's smtp server is refusing the connection. I'm presuming it's some sort of anti-relay measure. Putting the debugging hat on: I think I've got the address masquerading set up ok, but I am behind a NAT and have a dynamic IP address. The IP address would be within my ISP's allocated block, but doesn't resolve to their mail server obviously.
Anyone know if it's possible? Or are DreamHost super strict about accepting mail from NAT'd dynamic IP addresses?
On my laptop, I'm using Postfix and Slackware 12.2.