I have not ever had that happen (to me) but I did search-a-bit and found this as a possible answer for you (...OR not).

1. make sure your AUTOFILL is completely off
2. get an adblocker which blocks “web bugs”. (very small images)
——-
3. depending on operating system, you have a card in your Address Book / Contacts which is designated as You. change that You to another card which is fake


there’s a lot more that can be done. start with these

4a. Some browsers have SITE Preferences. this means you can
4b. block or allow javascript, cookies and more.
4c. One example is Omniweb for Mac.
4d. i have one browser set for Javascript to be off always . Advertising, login methods and malware often use Javascript

Chrome also has site preferences

https://support.google.com/chrome/answer/114662?hl=en&co=GENIE.Platform%3DDesktop

get a local geek to install one for you, if you are not technically inclined

but a third party cookie blocker is recommended.

depends on your operating system

I don’t know if there is a Windows equivalent

Javascript and Java are different.

Javascript is on nearly every webpage.

Java is obsolete, buggy and holey and flatly unnecessary

Gmail is popular but i gave it up

I believe both allow “aliased” addresses. my terminology may be incorrect

I use Gmail. I don't have Java or flash (is flash still around?).

I'll fiddle around tomorrow with some of your other suggestions.

Thanks

plus VPN networks such as NORD.