What is Spintax?

Last updated: April 24, 2026

Email variation is critical for deliverability. Sending identical email content at scale is one of the fastest ways to get flagged by spam filters — ISPs and email security tools recognize patterns and treat repeated identical emails as bulk spam. Historically, cold emailers solved this with spintax. Stamina solves it with AI.

What spintax is

Spintax is a templating system that randomly swaps words or phrases within curly braces to create variations of the same email. For example:

{Hi|Hello|Hey} {there|[firstName]},

Each send picks one option from each set, producing slightly different text per recipient. It was widely used to fool spam filters into treating each email as unique.

Why spintax falls short

  • Detectable patterns — Modern spam filters recognize spintax structure. The variation is mechanical and statistically identifiable at scale.

  • No real personalization — Swapping "Hi" for "Hello" doesn't make an email relevant to the recipient. It's noise, not signal.

  • Poor reading experience — Awkward spintax combinations produce unnatural sentences that damage credibility.

  • Doesn't scale with quality — More variation options mean more potential for grammatically odd or contextually wrong combinations.

How Stamina handles variation

Stamina generates genuinely unique email content for each lead using AI personalization signals — not templated substitutions. Each email is tailored to the specific prospect based on real data about their company.

  • Funding signal — References the company's most recent funding round

  • ICP fit signal — Explains why this specific company matches your ideal customer profile

  • Job post signal — References an active role the company is hiring for

  • Case study signal — Connects the prospect to a relevant customer win

Because the content is generated from unique data per lead, no two emails are identical — and the variation is meaningful, not mechanical.

What this means for your campaigns

  • No need to write spintax variations — Stamina handles uniqueness at the AI level

  • Better deliverability — genuine variation is harder for filters to flag than templated substitution

  • More relevant emails — content that references real company data performs better than random word swaps

  • Use A/B testing in Sequences for copy-level variation — test subject lines and CTAs to find what resonates