These pages go into more detail on exactly what an SPF record does, why you should flatten your SPF record, and why you should use an automatic tool to do so.
What is an SPF record?
Simply put, an SPF record tells other email servers that your email is genuine and shouldn’t be diverted to the user’s spam folder
Why flatten your SPF record?
SPF records have limits. If you exceed those limits then your entire SPF record is immediately invalid – that’s a very bad thing!
Why use automation?
How do you know when your email marketing tool changes their IP addresses for sending email? Short answer: you don’t!