Zip Component, Email Component, Encryption Component ActiveX Control for Zip Compression .NET Components for ASP.NET
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Index of Chilkat Blog Posts

October 29, 2007

Received Header Indicates an Unknown Host

When we send email using the .NET Email Component, the Received header indicates an unknown host:

Received: from SERV1 (unknown []) by (Postfix) with
ESMTP id 122149AB06F for <somebody>; Sun, 28 Oct 2007 11:34:11 -0400 (EDT)

We need to add the host name in the code to change from unknown to

The "Received" header field is not added by Chilkat (nor is it added by any email client). When Chilkat passes the email to an SMTP server (i.e. your SMTP server), it is the server that adds the "Received" header field. If there are multiple hops to the final destination, each mail server will add it’s own "Received" header field.

Therefore, it is not possible for the Chilkat component to modify what the SMTP server is adding.

The solution is to send from a computer having an IP address that the SMTP server can resolve to a hostname. This way, the SMTP server will report the hostname instead of the IP address.

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