550 after HELO
Philipp Ewald <[email protected]>
| Newsgroups | gmane.mail.imap.courier.general |
|---|---|
| Message-ID | <[email protected]> |
Hello, I'm attempting to understand why we're not seeing any error messages in our Courier mail log, despite knowing we're listed on a blacklist. We've noticed there are no errors, which seems to be linked to the receiving server not accepting the HELO command. After issuing "HELO," our connection gets rejected. According to RFC 2821 4.1.4, this shouldn't occur: "If the EHLO command is not acceptable to the SMTP server, failure replies of 501, 500, or 502 MUST be returned as appropriate. The SMTP server MUST remain in the same state after transmitting these replies as it was before receiving the EHLO." It was mentioned to me that the receiving server uses Exim, which should correctly handle this situation. Does anyone have insights into what might be happening here? I used the following command to test the connection: nc -C SERVER 25 >> 220 mx0.SERVER.de ESMTP (SERVER) (more power) Tue, 13 Feb 2024 14:09:17 +0100 helo SENDINGSERVER >> 550-REJECT: IP is listed in csi.cloudmark.com Kind regards Philipp _______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users