What Is SPF Flattening?

SPF Flattening is a process to take an existing SPF record that has multiple nested records and flatten the record to the point the record only contains a flat list of IP addresses or IP address ranges. Why do this? This is standard practice to make an SPF record contain fewer than 10 DNS lookups (SPF mechanism limit) and avoid the Too Many Lookups Error that will cause all emails to be rejected.

Does SPF Flattening Have Limitations?

Yes, traditional SPF Flattening does have limitations in that:

• Third-party senders are always adding new IPs: Traditional flattened records will not get updated IP address lists that third parties like Google, Office 365, SendGrid, etc., update. This can cause your emails to get rejected by recipients if you are missing those IP addresses.
• High overhead of managing it manually: Traditional flattened records require you to manually update them every time you add a new third-party sender or make any changes. This can be a lot of overhead, especially when you may not be sure which IPs match up to which senders/services.

What Solutions Overcome Traditional Flattening Issues?

To overcome the headaches noted in the section above, your best option is to look for a service that both flattens the SPF record and automatically monitors all of your senders, then updates your flattened SPF record.

MxToolbox's SPF Flattening Tool provides you with a simple, intuitive system to help manage your complex SPF configurations. As you add more third-party email sources, such as CRMs, Marketing Automation, Customer Support, Order Fulfillment, and other tools to your domain, you quickly max out of the allotted SPF configuration options. MxToolbox SPF Flattening removes the SPF limitations by automatically reconstructing your SPF record and helps your messages avoid dreaded DNS lookup errors.

How Does MxToolbox SPF Flattening Work?

MxToolbox SPF Flattening works by rewriting your SPF record. If you have more than 10 lookups included in your SPF record, the later lookups will not be executed, causing some of your legitimate email senders to bounce. Our SPF Flattening:

• Reviews the Verified Email Sources and manually added IP addresses currently in your SPF record.
• Traverses all the email senders included in your SPF record to generate a complete record of all needed IP ranges.
• Removes duplicate senders.
• Consolidates overlapping IP ranges.
• Crafts a compliant SPF record that covers all Verified Senders.
• Monitors for new email senders and automatically makes suggestions to include them in your SPF record.
• Provides ongoing sender verification.

MxToolbox's SPF Flattening is automatic and adaptive, enabling you to specify new Verified Email Sources and to have a new SPF record almost instantaneously. It is a feature of MxToolbox Delivery Center Plus, so simply subscribe to one of the Delivery Center Plus plans to access SPF Flattening!