SPF limits the number of terms that cause DNS queries during one evaluation.
Mechanisms and modifiers such as include, a, mx, ptr, exists and redirect can contribute according to RFC 7208’s processing rules.
Exceeding the permitted limit produces permerror.
Includes hide complexity
A short-looking record can exceed the limit because each provider include can recursively reference more DNS-triggering terms.
Count the evaluation path, not the number of words in the top-level TXT record.