A company is trying to send email to my "@btinternet.com" address but it keeps bouncing back. However, if I send them an email, same address, I get an auto-reply into my Spam. Why does this happen and how do I correct it? The company says the problem is at my end!
Have you tried adding the email address to your safe senders/allowed list? As this may override some of the checks done. Also I'm assuming the companies email domain has a SPF, DKIM and DMARC policy and that they are passing? You can check the email headers of the auto response to see. You can use https://mxtoolbox.com/emailhealth/ to help with this too.