SAME UITB   FAQ Support   Links Products   Services

News Contact Us About Us   Lists Downloads   Demos

Domain in MAIL FROM not for Email The Bogus MAIL FROM rule is used to check whether the domain specified in the MAIL FROM is a valid domain that can receive email. The MAIL FROM may be different from the From: address listed in the headers of an email, and is shown in a locally delivered email for EIMS by the Return-Path: header value EIMS adds at the beginning of a message. The substitution valid of %fd is the domain provided in the MAIL FROM command during the SMTP transaction. It is anything after the at sign ("@") in the MAIL FROM command received from the remote SMTP server. This domain is the host used to find a valid MX or A record for sending email to; the use of the Match Operator value of not_mx_host_ip_exists makes Denes look for a valid MX record for the host name, and if there are none then to check also for a valid A record for the host name. This is all accomplished with the single rule. With a Match String of *, the rule will basically match on any host name that does not have a resulting NS record of the type(s) discussed for the host name (note the "not" in the Match Operator to reverse the result of the asterisk in the Match String value). The only caveat about this rule is to make certain what happens when the MAIL FROM command from the remote SMTP server is NULL (empty). This is commonly done for automatically generated messages from the SMTP system, predominantly for bounce notifications (i.e. non-delivery notifications, or NDNs). In Denes, lookups on email with NULL MAIL FROM values can be disable with the preference Perform MAIL FROM Lookup When Empty. If enabled with with this preference, the %fd substitution for the host name value will be replaced with the preference value from Denes of MAIL FROM Domain When Empty. Proper setting of these preferences is vital to making certain this rule functions reliably (either disable the lookups or properly choose a substitution domain that will succeed).

The Cool Rule Rule Name: BogusMAILFROM Lookup Host/Format: %fd NS Record Type: MX Match Operator: not_mx_host_ip_exists Match String: * DNR to Use: 2 Check Authenticated: 2 Action: refuse Action Parameter 01: 550 5.7.1 RFC 2821 requires a valid mailbox as a MAIL FROM parameter (supplied "%fe"). Contact your postmaster to correct this problem. Download this rule with full entries in a separate text doccument.

Site designed and hosted by Deep Sky Technologies, Inc.. Any questions or problems with this site should be directed to webmaster@deepskytech.com.
Policies and Agreements