Send a hundred messages that differ only by first name and a filter sees one message sent a hundred times. Spintax is the cheapest way to break that pattern. Below: the syntax, where it came from, how the number of variants multiplies, where in a message to put it, and what it cannot hide.
What is spintax?
Spintax, short for spin syntax, marks alternatives inside curly braces, separated by vertical bars. When the message is sent, the tool picks one option from each set. Written as {Hi|Hello|Hey} {{first_name}}, the greeting comes out as one of three openings. The double braces are an ordinary merge field; the single braces with bars are the spin.
Each set of braces is a block. A message can contain many blocks, and in a good implementation each block spins independently on every send. That is what turns a handful of alternatives into a large number of distinct messages.
Where does spintax come from?
Spintax was built for SEO, not email. Plagiarism Today's history of article spinning traces the {a|b|c} syntax to tools that took one article and produced many reworded copies for link-building sites. Search engines treat that as spam. Google's spam policies list scaled content abuse, including content made by synonymizing or otherwise altering existing material, as a violation.
The email use is different in purpose. The message is still written for a real recipient, and spintax only keeps a sequence from repeating itself word for word. The lineage is worth knowing, though: spintax is a technique filters have long seen, not a disguise.
How much variation does a sequence need?
Enough that two recipients rarely get the same text. The number of distinct versions is the product of the alternatives in each block. If every option is equally likely, the chance that two given messages are identical is one divided by that product.
| Blocks | Options per block | Distinct versions | Chance two messages match |
|---|---|---|---|
| 1 | 3 | 3 | 1 in 3 |
| 3 | 3 | 27 | 1 in 27 |
| 4 | 3 | 81 | 1 in 81 |
| 5 | 3 | 243 | 1 in 243 |
| 6 | 4 | 4,096 | 1 in 4,096 |
Pure combinatorics, assuming independent blocks and equal odds. Real sequences repeat more, because some options are weighted or blocks are reused.
The table shows why independence matters. Three blocks that spin together give three versions; the same three blocks spinning independently give 27. Leadspicker's knowledge base puts typical spintax at roughly one repeat in 50 to 100 messages, and Leadspicker's own implementation at roughly one identical message in 150. That figure is reported, not derived from the table.
No mail standard defines spintax. The relevant documents describe how it is treated. Google Search Central's spam policies classify synonymizing existing content at scale as scaled content abuse, which covers spinning for web pages. The Distributed Checksum Clearinghouse documents fuzzy checksums that count how many copies of substantially the same message are being sent, which is why variation lowers but does not remove a bulk signal. Plagiarism Today records the syntax's origin in article spinning.
Where in a message should spintax go?
Wherever wording can change without changing meaning. Six places carry most of the variation:
- Subject line. Two or three phrasings of the same subject.
- Greeting. Hi, Hello, Hey, or the local equivalents.
- Opening sentence. The bridge into why you are writing.
- Transition. The phrase that moves from their situation to your offer.
- Call to action. Several ways to ask the same question.
- Sign-off. Best, Thanks, Have a good week.
Keep the facts fixed. Product names, numbers, claims and the personalised clause should not spin, because a wrong alternative there changes what the message says. Read every alternative in context once: a block that reads well alone can clash with its neighbours.
What spintax does not hide from a filter?
Spintax changes words, not the pattern underneath. Collaborative filters such as the Distributed Checksum Clearinghouse compute fuzzy checksums over the parts of a message that stay constant across many copies, so small variations do not stop bulk mail from being counted as bulk. A filter can also see the same sender, the same links and the same structure, whatever the wording.
- It does not fix volume. Too many messages per mailbox per day reads as bulk with or without variation.
- It does not fix relevance. Recipients who mark a message as spam do so because of what it offers, not its wording.
- It does not personalise. Variation is random; a clause about the recipient's company is not.
- It does not replace authentication. SPF, DKIM and DMARC decide whether a message is trusted at all.
With Leadspicker's spintax implementation, roughly one message in 150 is identical to another, against roughly one in 50 to 100 with typical spintax use.
Frequently asked questions
How much variation does a cold email sequence need?
Enough that two recipients rarely get identical text. Multiply the options in each block: three blocks with three options give 27 versions, so any two messages match one time in 27. More independent blocks raise that fast.
Where in a message should spintax go?
In the subject line, greeting, opening sentence, transition, call to action and sign-off. Keep facts, numbers, product names and the personalised clause fixed, so variation never changes what the message says.
Does spintax hide a message from spam filters?
No. It lowers the repetition of exact wording, but filters using fuzzy checksums count near-identical messages as bulk, and they also read sender, links, structure and volume. Spintax helps deliverability; it is not invisibility.
