Merging two SPF records

SPF is short for Sender Policy Framework. It is an authentication protocol which is designed to detect false and fishy sender addresses during email delivery. A problem with the SPF can have a direct impact on the performance of your email.

Having multiple SPF records as a sender is a straight and big NO when it comes to sending emails. It is therefore important to understand how we can merge two SPF records.

But why should we combine SPF records?

According to standard regulations, when an email is received the receiver is required to evaluate one SPF record. Having multiple DNS SPF records would mean that you have no control over which record is being evaluated by the recipient at the time of reception. This is highly likely to throw a bad result and your email may not be delivered. 

v=spf1 a mx include:_spf.adcrux.io -all 

The “-all here disallows all the other senders to send emails using your domain.

The above SPF record allows a service like Adcrux to send emails using your domain. This type of a record is typical for all Adcrux users.

Whenever you create a domain for email delivery you have an SPF record. So, to allow Adcrux to send and receive emails we must add the Adcrux as a new rule to your existing SPF record. To put it simply, we must merge SPF records.

How can you merge SPF records?

SPF records can be merged by combining the “rules” in both SPF records. A rule in an SPF record is a major part of the record. 

It consists of majorly 3 things: 

  1. An Optional Prefix
  2. The Mechanism
  3. An Optional Value

In cases where the prefix is not set, the default condition is “+” (pass). A colon separates the mechanism and optional value.

The “v=spf1” part is the modifier. Modifiers use the “=” for separation and not a colon.

Let us start by creating our new merged SPF record. Follow simple steps and you’d be done with it in no time. 

Step 1: An SPF record must start with a “v” modifier, so let us retain that as the start of our new SPF record. 

v=spf1

Step 2: Now we add both the initial google rule and the new rule for adcrux into our to-be merged SPF record. 

v=spf1 include:_spf.google.com include:_spf.adcrux.io

Step 3: Next we need to restrict all the other domains from sending emails and as discussed above, we can use the “-all” rule for this. This mechanism must be added at the end of your record because SPF is evaluated from left to right. 

v=spf1 include:_spf.google.com include:_spf.adcrux.io -all

Here, we have now created our new SPF record. This would overwrite and replace the old SPF record that your domain may have. This will allow Google and Adcrux to send emails using your domain. Other senders are blocked using the “-all” rule. 

Once you are done with these changes, we suggest that you use an SPF validator here to check your record for any discrepancies. 

Have any more doubts, send us an email at [email protected] and we’ll get in touch!