Jeremy Harris <jgh@???> (Fr 14 Nov 2014 11:29:09 CET):
> On 14/11/14 10:10, Heiko Schlittermann wrote:
> > Currently it seems that they are not able to reject at RCPT, they
> > reject after DATA: "550 5.1.1 User unknown".
>
> One has to wonder what the Exchange response to an SMTP session
> with one good, one bad RCPT is.
It just rejects the complete message… It means, if I send a message to a
couple of users, just one non-existing recipient in this list causes a
permanent delivery error for the complete message. More - the sender
sees "User unknown", and does not have any chance to find out about
which user the Exchange server is talking…
I just think of bunch of mailinglist subscribers, all are working in the
same company, thus having the same domain…
One good:
<- 220 [hidden] Exchange
-> EHLO nbox
<- 250-exchange.[hidden].de Hello [10.0.8.2]
...
-> RCPT TO:<peter.[hidden]@foo.[hidden].de>
<- 250 2.1.5 Recipient OK
-> DATA
...
-> To: peter.[hidden]@foo.[hidden].de
...
-> .
<- 250 2.6.0 <0c526eba-1890-4029-8302-c48c8f7cfad9@???.[hidden].de> [InternalId=1481763717166, Hostname=Exchange.ad.[hidden].de] Queued mail for delivery
-> QUIT
One bad:
<- 220 [hidden] Exchange
-> EHLO nbox
<- 250-exchange.[hidden].de Hello [10.0.8.2]
...
-> RCPT TO:<foo@foo.[hidden].de>
<- 250 2.1.5 Recipient OK
-> DATA
...
-> .
<** 550 5.1.1 User unknown
-> QUIT
One good and one bad:
<- 220 [hidden] Exchange
-> EHLO nbox
<- 250-exchange.[hidden].de Hello [10.0.8.2]
...
-> RCPT TO:<peter.[hidden]@foo.[hidden].de>
<- 250 2.1.5 Recipient OK
-> RCPT TO:<foo@foo.[hidden].de>
<- 250 2.1.5 Recipient OK
-> DATA
...
-> .
<** 550 5.1.1 User unknown
-> QUIT
Best regards from Dresden/Germany
Viele Grüße aus Dresden
Heiko Schlittermann
--
SCHLITTERMANN.de ---------------------------- internet & unix support -
Heiko Schlittermann, Dipl.-Ing. (TU) - {fon,fax}: +49.351.802998{1,3} -
gnupg encrypted messages are welcome --------------- key ID: 7CBF764A -
gnupg fingerprint: 9288 F17D BBF9 9625 5ABC 285C 26A9 687E 7CBF 764A -
(gnupg fingerprint: 3061 CFBF 2D88 F034 E8D2 7E92 EE4E AC98 48D0 359B)-
