SPF Workflow on Email
We all know that SPF is a needed record for Email servers. In this Article we will discuss about the work flow of SPF record.
Sender Policy Framework is a global standard, to provide an approved sender list for a domain.
In this process, a receiving email server ISP can check whether the sender is authenticated to send emails on behalf of the sender domain. In case of mismatch from the sender and the domain authentication, the emails can be treated as spam.
SPF does not work on the basis of the “from” address, It works on the “return path” of that particular email. A return path is an email address which the receiving domain uses to notify the email delivery related queries. SPF is a factor based on which the receiving ISP determines whether the server should allow or deny the delivery.
Note that, an email without an SPF also can deliver to receiving server, But using an SPF will make you more trustworthy for the receiving ISP’s. It also helps to resolve the bounce back and spam abuse to an extent.
How does an SPF work:
SPF works by checking a DNS record which contains the approved senders or IP’s for a domain. It checks the return path of a message header and determines whether this sender is approved to send emails on behalf of the sender domain.
The below structure will help you to understand the workflow of an SPF:
** See the structure as explained in the figure**
Explanation of an SPF record:
Let's explain the details of an SPF record and its working.
v=spf1: It determines the SPF version.
a: It validates the A record of the sender domain and approves the IP merged in the A record.
Include: This is for the value of an SPF record for the specified domain. This is also a set of IP’s which are incorporated with the SPF value.
~all: This states that everything else rather than the value is subjected as a softfail. These emails will be received in the recipient server by a softfail mark and the receiving ISP can take necessary action for the same, such as mark it as spam.
- all: This directly rejects the email if mismatched with the value of an SPF.