On 23/10/2003 at 12:42:50, Barry Campbell wrote: > No transport provider was available for delivery to this recipient.
> Even this wouldn't be such a bad thing but it doesn't give you any > indication which of the addresses are bad! You have to test each > address individually to identify the one with the issue. > I did find a similar issue with sendmail that seems to be related to > the way that Outlook handles the response from the mail server. > Apparently Microsoft didn't follow the standard to the letter! > *!GASP!* Yep, that's pretty much it. The relevant part of an SMTP session looks (from the client side) something like: Out: RCPT TO:<address1> In: 220 OK Out: RCPT TO:<address2> In: 550 User unknown Out: RCPT TO:<address3> In: 220 OK So each recipient address receives its own OK/error response, and it's entirely possible for a mail client to identify which addresses were accepted and which were rejected. It's also possible to identify why they were rejected (the text after the 5xx code) and return that to the user. Outlook chooses not to do any of that, and returns the 'no transport provider' error for everyone instead. This is an Outlook issue, not an IMail one. As you found, it happens with Sendmail too (and every other SMTP server that doesn't blindly accept all mail and later bounce it). Cheers, Evan To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
