Adding SPF records
Note: Microsoft Sender ID is in many ways similar to SPF, and in most cases, SPF and SenderID are compaible, so by making an SPF record, you are also creating a Microsoft SenderID record, that sometimes causes trouble when the envelop sender is not the same as the From address !
Here, i will start by showing you a list of SPF records, and what they mean to mail servers, You can use those SPF records or compose your own, as the syntax is very simple really.
If you do not want to take chances, you can use the SPF generator at openspf.org
For example, the most common SPF record is
"v=spf1 a mx ~all"
–Explaining the line above, v=spf1 means that this is an SPF TXT record, it is common to all SPF records,
–followed by an a that means “any computers in the A record fields of the domain’s DNS are allwed to send email, or more simply put, to allow your web server (where you may run PHP scripts that send email for example) to send emails on the domain’s behalf
— Followed by an mx which means all servers mentioned in DNS as mail servers for this domain, are also allowed to send email on this domains behalf.
— ~all means that this loosly describes all servers that can send email on this domain’s behalf (softfail), while a -all would mean that this strictly describes all servers that send mail on our domain’s behalf (fail), and a ?all means that this describes some of the domains allowed to send email on our domain’s behalf, notice that ~ is not – from 1 and 2, ~ is loosly, – is strictly.
But for our examples sake, let us look at a longer, expanded SPF record and see what the extra fields mean
"v=spf1 a mx a:xxx.xxx.xxx.xxx mx:mailsrv2.example.net ip4:yyy.yyy.yyy.yyy/24 ip4:xxx.xxx.xxx.xxx include:mailsenders.com ~all"
In the example above, the section that reads mx:mailsrv2.example.NET is a mail server that is also allowed to send email on example.COM’s behalf
a:xxx.xxx.xxx.xxx where the masked charracters are an IP address means that the server or mail sender with the IP address mentioned can also send email, you can add as many such sections separated by a space as you wish to allow many computers to send mail on the domain name’s behalf