Rephrasing changes one number, and deliverability isn't it
You drafted one outreach email and a script sent it to the list. Somewhere between composing it and sending it, a guide told you to include a few synonym groups, so you wrapped the opener and the value line in braces and continued. What nobody noted is which number those braces shifted, and the honest answer changes what you do next: the thing spinning measurably alters is how many people on your list hold a message that somebody else on the list also holds.
The figure nobody mentions is the share count
Run a list through a template with synonym groups turned on a few at a time and two columns come out. The first is how many unique messages the pool holds. The second is how many recipients got a text that at least one other recipient also received, and that column behaves nothing like the first. A template with a scattering of active groups yields a comfortable-looking tally of possible messages on paper while nearly every recipient still shares theirs with someone, because the draws collide long before the arithmetic runs out. The blog measured this on the open engine instead of arguing it, and the measured columns sit within a few messages of what the birthday-style formula predicts.
The cost lands on the text, in two spots
One flaw a machine can spot: two adjacent groups pick words sharing a root, the picks fall a few words apart, and the sentence seems as though it was composed rather than penned. A lint with a narrow window and function words omitted finds those, and the count climbs as more sentences carry a group. The other flaw no lint will catch, because it is agreement rather than repetition. Every option can be valid on its own and still produce a sentence that does not parse once a adjacent group swings the other way, since the verb picked in one slot wants a preposition the other slot removed. Nothing is off where you wrote it and nothing flags where you render it; the error exists only in the combination, and the practice that spots it is to fork the tiniest span that genuinely differs and read a handful of renders rather than the first one that came up.
Whatever you spin, part of every message is a constant. Take the comparison the other way and measure how much of each send is text that recurs in almost every other send, and what stays is the section at the bottom: the name, the company, the booking link, the unsubscribe. It is minor as a share, and it is the part the provider rules actually touch, since the unsubscribe rests there and the authentication belongs to the domain. Spinning is protection against a text fingerprint, and it pays exactly what that fingerprint is worth to a filter whose settings nobody outside the provider has seen.
The readings, the charts and the document that generates them: manual outreach extension
The order that works is short. Take the amount of variation from the size of the list rather than from a reference, and earn it with order and form before vocabulary: a permutation of a few items is many results from one edit and it varies length rather than words, while a condition varies what the sentence states from a field in the row. Neither construct survives a sending tool that parses flat braces and nothing else, so render first and transmit the finished text. Then read a few of them aloud, and leave the block that never varies be.