I’m fairly certain they are. My links ended up indexed in Bing search results. The only place they were ever rendered was in private emails to users. Bing should not be indexing that.
You're right, it shouldn't. It's possible that they're fetching these URLs from their customers' browsing history and submitting those (external submissions follow different crawling rules, sometimes bypassing robots.txt). Bing's webmaster information says so, at least: https://www.bing.com/webmasters/help/webmasters-guidelines-3...
For a bit of added "fun", Google will do the same, but if you add a page to robots.txt and set noindex then they won't process the noindex parameter and external indexing sources might still generates search results: https://developers.google.com/search/docs/advanced/crawling/...
jeroenhd|3 years ago
For a bit of added "fun", Google will do the same, but if you add a page to robots.txt and set noindex then they won't process the noindex parameter and external indexing sources might still generates search results: https://developers.google.com/search/docs/advanced/crawling/...