* Chris Lightfoot wrote (06/12/06 10:12):
> On Wed, Dec 06, 2006 at 10:53:55AM +0100, Matthias Waffenschmidt wrote:
> [...]
>> The decision whether a failure is temporary or permanent is not up to
>> you but up to the server that sends the response.
>
> only if it gets it right!
>
I suspect that another good "rule of thumb" is that it's impolite to
assume that your server knows better than the rejecting server, even if
that might often be the case.
After all, if an e-mail is bounced with a 550 quota full message, the
original sender can normally opt to resend if they feel like it. Users
aren't constrained by RFCs (as far as I know).