I’m trying to add a new ESP to my SPF record. Their instructions tell me to create a new SPF record, but I already have one for my domain. How many SPF records is too many for one domain?
Each domain can have only one SPF record. If a domain has created more than one, all records will be invalidated. For more information: reference this fraudmarc.com blog post on multiple SPF records: https://www.fraudmarc.com/multiple-spf-records/