Recently I became aware that emails sent to me from a regular friend were not arriving - not via the BT site using Chrome, not via Mozilla Thunderbird, not via gmail on my tablet. When I accessed the BT site via IE (which I rarely/never use as it's so slow) they were all in Spam!!! How can this happen and what can I do about it as it's more than annoying? Emails from loads of other people were arriving normally via all routes.
But why should using a different browser get the emails "spammed" by the BT server? When you say "something in the emails" - do you mean the content? I can assure you that there was absolutely nothing dodgy in the emails!
Browser can't affect spam. Only email servers and clients check that ( or some AVs.) Sounds like the BT server is doing it. Must be something it's triggering on.