SPF is a TXT record published on your domain that allows specific servers to send mail by using your domain name. In this case, Active Campaign auto-configures SPF for everyone which means manual creation of SPF record is not needed even if your domain is a custom domain.
Adding an SPF Record for Active Campaign
Login to your DNS management console
Navigate to Tools & Settings > DNS Template
You need to edit the DNS TXT record related to SPF
An SPF TXT record for Active Campaign will have the following syntax:
name.domain.com TXT v=spf1 include:emsd1.com -all
Publish this record in your DNS records section for your respective domain.
Note: If you don’t have an SPF record previously for your domain, simply publish the above-mentioned record to enable SPF for outgoing emails using Active Campaign. If you do have an existing SPF record in your DNS, you need to modify it to include Active Campaign, as shown below:
Previous SPF record: v=spf1 mx -all
Modified SPF record: v=spf1 mx include:emsd1.com -all
Wait for 72 hours to allow your DNS to process the changes