Setup automatic tracking
AutoSPF can be used for free to manually "flatten" any SPF records. However most people will want to have their SPF records automatically flattened and managed.
Register for a free account at https://www.autospf.com/register
After registering for a free account, add any domains whose SPF you want to flatten / manage. A domain must have an existing valid SPF record in order to be added:
In this example, we add the "amazon.com" domain, and use AutoSPF to "flatten" its various records. (Note that in manual mode, no DNS changes are made or served, meaning the tool is only used for flattening, and effecting change depends on the domain's DNS administrator - This is why we can use amazon.com for our example without impacting the real amazon.com)
Import DNS SPF record into system
The current DNS-based SPF TXT record is displayed. As per the illustration below, change the slider from Use domain record to Use saved record to unlock the ability to edit the record. Make any necessary changes, and click the green "Save" button:
Having saved, you're now able to view both the SPF record retrieved from DNS, and the static version of this record as saved within AutoSPF's system. Note that toggling checkboxes for the various includes only changes the content of the SPF record saved in AutoSPF's system.
Update DNS records with flattened records
Having stored your SPF record within AutoSPF's system (above), follow the instructions under "Automatic setup" - simply replacing your existing SPF record with the record provided.
Making intentional changes
To update your SPF record (adding a new include for salesforce.com, for example) use the AutoSPF UI to manually add IP ranges or includes, and save your changes. No further changes to your DNS records are required, AutoSPF will automatically update your flattened SPF record.
Updating following provider updates
If you're using includes within your SPF record to include provider IP ranges, and your provider changes their IP ranges, AutoSPF will automatically update your flattened SPF record accordingly. You don't have to do anything.