craig@LOKI.BBN.COM (Craig Partridge) (05/28/86)
> There are no hard rules on this and our implementation chooses to reject > mail where the only host specified is unknown. UNIX is not so rigorous, > it will accept mail from (or for) any host whether it exists or not, and > will then have no way of informing anyone but the mail system maintainer > that there is a problem. We like the TOPS-20 system better where the > originator has to resolve the problem. Joel, I generally agree with the goal but do want to point out that our experience at CSNET is that, more often than not, the problem is not the originator's but that of the receiving mail system, which either has out of date host tables (presumably under domains this problem will become one of having a defective or ill-informed nameserver) or some configurational error which causes it to reject the message. Craig Partridge CSNET Technical Staff