450 Helo command rejected: Host not found
Above is the error I get in mail.log, details edited to protect the innocent.
Dec 23 15:28:55 mail postfix/smtpd: NOQUEUE: reject: RCPT from mail.incomingdomain.org[123.456.789.123]: 450 4.7.1 <hostxx.internalsubnet.incomingdomain.org>: Helo command rejected: Host not found; from=<email@example.com> to=<firstname.lastname@example.org> proto=ESMTP helo=<hostxx.internalsubnet.incomingdomain.org>
The following are turned on in the global settings:
- Hostname in greeting violates RFC (reject_invalid_hostname)
- Client's IP address (reject_unknown_client)
- Hostname in greeting (reject_unknown_hostname)
- Sender's domain (reject_unknown_sender_domain)
The two FQDN options are off since so many people can't configure a DNS server correctly.
Anyway, is there a way I can allow matching domain.com type addresses through? All of a sudden recently (last couple weeks) this has been rather common.
Mail | Dell 2950III | 2x Quad Core 5420 | 8gb RAM | 6x 146gb SAS RAID 0+1 | Red Hat 5.3 | Zimbra 6.0.10 Network Edition
Test | VMware ESXi Whitebox | Phenom II Black 3.2ghz | 12gb RAM | 6x 1tb SATA RAID 0+1 | CentOS 5.4 | FOSS, Not in use now