Spintax is template syntax like {Hi|Hey|Hello} that rotates words so no two sends are identical. A deliverability tactic meant to keep bulk cold email from pattern-matching as bulk.
Should you: lightly, if at all. Modest variation can help large sends avoid template fingerprinting, but filters increasingly detect spintax-style patterns themselves, and mangled grammar from careless spins reads robotic. The opposite of what wins replies. Practitioner consensus in 2026: clean, human copy beats any amount of spinning.
The better version of the same idea: real segmentation. Three genuinely different emails for three genuinely different audiences outperforms one spun template pretending to be personal.