]SK[, on 31 July 2012 - 08:22, said:
I'm sure all you get is a DNS address resolved to an IP with any Dynamic DNS service.
The only way I can think is to have an alias such as mx0.example.com which is a CNAME of test.no-ip.org. mx0.example.com will then need to be a record itself. I guess you could also just have test.no-ip.org as your only MX record.
My first thought though would be to test the possibility of receiving and sending on port 25. I would have thought most domestic ISP's will block this communication.
Not all do. Time Warner for example leaves the port open but adds its residential IP blocks to one or more DNS Block lists, so that all mail that comes from them gets marked as spam by receivers who check against said lists.
I'd imagine using something like DDNS probably would cause a similar issue. Though idk.