MAIL FROM:<a> 250 ok RCPT TO:<b> 250 ok RCPT TO:<c> 450 try later RCPT TO:<d> 550 no such user DATA blah blah . 554 ugh
Which, if any, of b, c, and d get retried? Why or why not? What if the 554 were a 450?My take FWIW, is that none should be retried because the data is rejected (probably based on content analysis e.g. spam or virus). If the data response were a 450, a+b+c should be retried.
But 554 can mean all sorts of things. Maybe it was a content failure, maybe there was some screwup storing the mail. Or let's say it was a 552 which can mean mailbox full. Now what?
Like I said, this gets really twisty. Regards, John Levine, johnl@xxxxxxxxx, Taughannock Networks, Trumansburg NY "I dropped the toothpaste", said Tom, crestfallenly.