[x]
Posted via EE Mobile

Search, ask, and monitor your questions on the go with EE Mobile. Visit Experts Exchange from your mobile device and never be out of touch again.
07/10/2008 at 09:11AM PDT, ID: 23554355
[x]
Attachment Details
[x]
The Solution Rating System

With so many solutions, how can you tell which solutions are most likely to help you and which ones are not? To provide you with a tool to use, we rate our solutions based on various elements that most accurately determine if a solution is a quality solution. To explain what factors affect the solution rating, here are the elements we take into consideration when formulating our solution rating.

  • The Grade of the Solution
  • The Zone Rank of the Expert Providing the Solution
  • The Number of Author and Expert Comments
  • The Number of Experts Contributing
  • The Feedback of the Community

Your Input Matters
Because of the way the system is set up, the most important variable in this equation is you. As a member of Experts Exchange, you are able to cast your vote on the quality of the solutions in regard to how complete, accurate, helpful and easy to understand each solution is. When you provide your feedback, each rating is adjusted accordingly. So, if you see a solution that has a poor rating that you think is a good solution, let us know by rating it. As you do, the rating will be adjusted and will become more accurate for other members of our site.

If you have any suggestions that you would like to make for our rating system, please ask a question in the Suggestions Zone of Community Support.

Thank you!
7.8

Question regarding SPF (Sender Policy Framework)

Asked by kam_uk in Domain Name Service (DNS), Email Servers, Anti-Spam Email Software

Hi All

I have some queries regarding SPF and would be grateful if anyone could help me clear them up.

Now, as I understand it, SPF it another type of DNS record that helps prevent forgery by detailing which servers are permitted to send email from the domain the SPF record belongs to.

Let's take the following scenario; A user at Company A is trying to send mail to a user at Company B. Each company has an Exchange server and an SMTP Gateway.

User A > Exchange.companyA.co.uk > mail.companyA.co.uk ---- INTERNET ---- mail.companyB.co.uk > Exchange.companyB.co.uk > User B

Questions

a) Where does SPF checking take place? At the SMTP Gateway of CompanyB or the Exchange server?

b) What if Company A does not have any SPF record registered in DNS? I understand this is purely optional at the moment.

c) What are the possible SPF variations? So far, I think there are;

CompanyA.co.uk  TXT "v=spf1 mx -all" would cover all servers in CompanyA.co.uk with an MX record.
CompanyA.co.uk TXT "v=spf1 ptr -all" would cover all servers in CompanyA.co.uk with a PRT record

How could I list only mail.CompanyA.co.uk as permitted to send mail from CompanyA?

d) Ignoring SPF for a minute, is there any reason why a sending SMTP server should be listed in a domain's MX record if it is unable to receive mail?

e) If Company A does not have an SPF record, but Company B does, does this make any difference to the SPF checking carried out by Company B?

f) How does Company B actually set up SPF checking?

g) If Company A does not have an SPF record, are there any checks out there that verify if Company A's sending SMTP server is listed in its MX record? I understand MX is for recv'ing mail only, so not sure what the relevance of MX in forgery is?

Hope someone can help!

Thanks!
[+][-]07/10/08 09:27 AM, ID: 21975043

View this solution now by starting your 30-day free trial. Setting up your free trial is quick, easy, and secure. We will return you to this solution, unlocked, when you're done.

 

About this solution

Zones: Domain Name Service (DNS), Email Servers, Anti-Spam Email Software
Sign Up Now!
Solution Provided By: ravenpl
Participating Experts: 4
Solution Grade: A
 
 
[+][-]07/10/08 09:31 AM, ID: 21975097

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/10/08 09:34 AM, ID: 21975129

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/10/08 10:07 AM, ID: 21975511

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
 
Loading Advertisement...
20091111-EE-VQP-91 / EE_QW_2_20070628