On 24 Mar 2005 at 14:05, Marc Sherman wrote about
"Re: [exim] Heads up?":
|...
| Just to follow up on this, I've been experimenting with my own spam
| rejection system today, and discovered that at least Exchange severely
| limits the size of the text it will display in a bounce caused by a 550:
That's not as brain damaged as some MTAs out there. At least it
shows part of it.
|...
| The error message I sent back ended with " assistance." but that was too
| long. So if you try to implement a c/r system using 550 responses to
| send the challenge,
... don't expect it to work.
| the url to respond to the challenge had better be
| pretty small.
Exchange at least shows part of the actual response. Other systems
don't even do that much. And then there's the point that many users
won't read the DSN carefully enough to spot your text even if it is
all there.
- Fred
