Hi Heike, Make sure Exchange recipient filtering is turned on. This is done in different ways depending what version of Exchange you have. This page may get you started:
https://www.aussiecom.com.au/support/index.php?/Knowledgebase/Article/View/2/2/how-to-configure-exchange-to-properly-reject-emails-to-invalid-users Regards Richard -- Richard Rogers Principal IT Officer, Client technology and Applications Information Services, Staffordshire University -----Original Message----- From Heiko Schlittermann Sent: 13 November 2014 12:38 Hi, we are about to forward messages from outside to an internel Exchange2013 server. It seems that the Exchange2013 does not cooperate well with the callouts for recipient verification: mail from:<[email protected]>250 2.1.0 Sender OK rcpt to:<empfang@empfangsdomäne.local> 250 2.1.5 Recipient OK data 354 Start mail input; end with <CRLF>.<CRLF> Test . 550 5.1.1 User unknown <------------- TOO LATE for Exim -- The "User unknown" response is delayed until the end of the data phase. Can anybody confirm this behaviour? Was anybody successful in changing the behaviour to what Exim expects (5xx already at RCPT time)? Yes, I know, using cutthrough routing/delivery could partially solve my problem. But it's limited to one recipient per message, if I got it right. 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)- -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
