SPF record question
I asked for a number of SPF records to be created including this one (yes, I've modified the real domain and IP - I don't really work for contoso):
"v=spf1 ip4:x.x.20.20 ~all"
Using a SPF wizard on their end, the other guys came up with this:
"v=spf1 a:smtp.contoso.com ip4:x.x.20.20 ~all"
From: http://old.openspf.org/wizard.html?mydomain=contoso.com
Question:
Will that reference to "a:smtp.contoso.com" have a negative effect? Or is that perfectly fine?
smtp.contoso.com is simply the FQDN of the mail server (external IP of the firewall in fact). I think they considered it as ANOTHER server that might send on behalf of contoso.com.
May 6th, 2011 1:14pm
Yes because during the wizard it asks if there are any other servers other than your mx servers that send mail and they just give an example like "smtp.company.com" If you don't have it just delete the example.
"Do any other servers send mail from company.com? a: smtp.company.com" (if there is no smtp.company.com you want to delete it)
For example companies have mx records but they also have mail servers that they use just for outbound so there is no mx records for these so you would want to add them in manually.
James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com
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May 6th, 2011 2:43pm
Yes...?
Meaning "negative effects" or "perfectly fine" (although perhaps unnecessary)?
May 6th, 2011 3:20pm
There is no negative affects it's just unecessary.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com
Free Windows Admin Tool Kit Click here and download it now
May 6th, 2011 3:24pm
On Fri, 6 May 2011 17:08:02 +0000, Le Pivert wrote:
>
>
>I asked for a number of SPF records to be created including this one (yes, I've modified the real domain and IP - I don't really work for contoso):
>
>"v=spf1 ip4:x.x.20.20 ~all"
>
>Using a SPF wizard on their end, the other guys came up with this:
>
>"v=spf1 a:smtp.contoso.com ip4:x.x.20.20 ~all"
>
>From: http://old.openspf.org/wizard.html?mydomain=contoso.com
>
>Question:
>
>Will that reference to "a:smtp.contoso.com" have a negative effect? Or is that perfectly fine?
>
>smtp.contoso.com is simply the FQDN of the mail server (external IP of the firewall in fact). I think they considered it as ANOTHER server that might send on behalf of contoso.com.
If the IP address of smtp.contoso.com is x.x.20.20 then there's no
need for the a:smtp.contoso.com in the TXT record.
You should have a SPF record for the domain smtp.contoso.com, though.
That would allow for the checking of spoofed HELO\EHLO data (assuming
your server identifies itself properly).
---
Rich Matheisen
MCSE+I, Exchange MVP
--- Rich Matheisen MCSE+I, Exchange MVP
May 6th, 2011 3:44pm
Rich,
Yes, that is one of the SPF records I had created.
James, Rich,
Thanks to both of you for the clarification.
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May 6th, 2011 3:52pm