Solved

Query on SMTP headers

Posted on 2009-05-08
2
433 Views
Last Modified: 2013-11-30
Hi Guys

When I check the message headers of an email, I see text such as this:

Received: from mail.mydomain.net ([83.170.88.1]) by bay0-mc5-f6.bay0.hotmail.com

How are these values worked out? I expect Hotmail knows the IP. 83.170.88.1, that is connecting to it, but how about the hostname, mail.mydomain.net? Is that what is mentioned in the EHLO, or does the Hotmail server carry out a reverse DNS check on that IP address?
0
Comment
Question by:kam_uk
2 Comments
 
LVL 12

Expert Comment

by:Steve
ID: 24335597
yes.. all mail servers will do a reverse lookup on IP address to ensure they are configured correctly.
0
 
LVL 2

Accepted Solution

by:
bruce_77 earned 500 total points
ID: 24402428
That is how the SMTP client announces itself to the SMTP server...so - yes - in the EHLO/HELO SMTP command.

The SMTP server doesn't form this value from a rDNS check.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

What is Usenet? There are many different opinions on exactly what Usenet is an isn't. Many opinions are incorrect simply out of ignorance. The Wikipedia listing about Usenet does a good job of explaining it, so instead of repeating it all here I wi…
Resolve Outlook connectivity issues after moving mailbox to new Exchange 2016 server
This Micro Tutorial hows how you can integrate  Mac OSX to a Windows Active Directory Domain. Apple has made it easy to allow users to bind their macs to a windows domain with relative ease. The following video show how to bind OSX Mavericks to …
Along with being a a promotional video for my three-day Annielytics Dashboard Seminor, this Micro Tutorial is an intro to Google Analytics API data.

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

18 Experts available now in Live!

Get 1:1 Help Now