On 7/17/11 9:18 PM, Always Learning wrote:
Legitimate senders should not use fake, false, misleading credentials.
There is no requirement for the greeting name to match any IP, and isn't likely to work for multi-homed and/or clustered machines.
Which type of 'multi-homing' were you thinking about ?
http://en.wikipedia.org/wiki/Multihoming
- Single Link, Multiple IP address (Spaces)
- Multiple Interfaces, Single IP address per interface
- Multiple Links, Single IP address (Space)
- Multiple Links, Multiple IP address (Spaces)
Multiple interfaces, multiple IP addresses. Sendmail isn't going to track which interface it is sending on and adjust its greeting.
Which type of 'cluster' were you thinking about ?
http://en.wikipedia.org/wiki/Computer_cluster
- High-availability (HA) clusters
- Load-balancing clusters
- Compute clusters
If any of these share the same IP address, they can share the same host name.
There are any number of topologies that use multiple IP addresses for what appears to be one name. A load balancer might be involved, they may or may not accept on the same IP's as they use for outbound connections, they may or may not know the outbound ip.
I am not well acquainted with either of the above two methods, multi-homed and clusters, but I can not understand why any of them should resort to using fake identities when sending-out emails.
Just because it doesn't match the IP doesn't make it fake.
Can you help me understand why bogus identities are necessary in these circumstances ?
You are the one defining it as bogus. Consider a system where one or more of it's routes to the internet go through nat routers or the nat functionality of a load balancer. The program sending the mail won't even know the IP you see.