How much spintax in a cold email is too much, measured on 500 sends
Gmail and Outlook's bulk sender rules never mention synonyms. What spinning changes in a cold email, where it stops helping, and how many groups 500 sends a day need.
Scaled content abuse: what Google means by it, and what that makes of spintax
Google's spam policy names synonymizing as an obfuscation technique. Fifty generated pages, measured: what a spinner does to them, and the test that shows it.