Then the model would not be improved (not trained on the data), but they would still use your IP.
Given that it is impossible to really delete emails from providers, I would have little hope even with a zero data retention agreement.
Proof of training or RAG search on data that was private would be a huge smoking gun and would change usage habits overnight.
Take Tristan Buckmaster, he is asserting OAI may have used his data to arrive at their proof. They initially said they couldn't say and then they amended their statement. So it's their word against his, but they showed no evidence and invited exactly zero independent 3rd parties to attest to this. Buckmaster would likely have to sue them to hopefully force their hand by court order. From our purview, he likely won't pursue legal counsel and OAI won't admit to using unauthorized content to train their models. We should likely accept that all AI corporations are using all data available to them full stop.
Think about it, these model interactions have been the frontier of human feedback across all disciplines and modalities. The sheer immensity of data flowing into their servers of human original content (with feedback) is likely much greater than what they scraped from the web or are continuing to scrape. Entire codebases being shared, entire business processes, reasoning behind said processes and a load of industry specific secrets have likely been shared in the interactions. The rise of agents with sub-agents each with minimal guardrails have gifted the models with the ability to exfiltrate all this data with the user consent and a minimal non-enforceable "do not train" check-mark that the unsuspecting user is unlikely to be able to show any harm later.
Their acquisition techniques prior to larger user bases included ample piracy. Anthropic (the holier than thou of the two) itself, has had to settle at $1.5b for using pirated books in training, why wouldn't they use every available avenue to help their models improve today legal or otherwise?
If data is being sent over the wire, assume someone is going to use it to improve their models. They all include a clause of 30-Day retention on pretty much on all user data to ensure "abuse" isn't happening. So they are using it, and telling you about it, not using data for model improvement is just cope for the user.