- Your real name
- Your real email address
- Your real salary and job title
- Your normal vocabulary and idioms
- Any of your devices (as in, go to an internet cafe or something)
They can deanonymize as much as they like all they're going to find is that "dbcooper42069[at]hotmail", using non-region specific language, took a very dim view of company X's management style and pay rates.
In any case the idea of a company email is a little hard to define from the perspective of a 3rd party that deals with millions of companies; different TLD's, domains, sub domains etc make it very hard to nail down exactly which pattern is the definition of any given companies real email addresses.
I think that this one is way harder to avoid than you might think, short of having someone else write the review for you (which might not be a bad idea!).
The other thing I can think to try to do would just be avoid any complete sentences, just give short bulletpoints or something. Resticting the amount of text should make it harder to get anything like a real match.
In a few reviews I've left (using different accounts etc for each one to avoid fingerprinting!) I've written the review myself, changed it to a formal register, thesaurus-ed a few words, and also threw in a few red herrings to make which team I was from appear ambiguous (for example, whine about sales tooling/CRM when you're an engineer that has nothing to do with sales).