When you get a link in your email, and you've decided that the email is genuine, should you click on the link they give you?
Probably not. Especially when the link is going to a URL that isn't the company URL.
So when I got my monthly email from TalkTalk telling me about my latest bill, I saw a link to "Visit MyAccount". But the link didn't go to talktalkbusiness.co.uk, it went to s2431.t.en25.com
A whois on that domain, returned "Oracle Corporation", not TalkTalk.
This is about as suspicious as it gets. But the info in the email also gave my correct account number, name and billing amount. So how could it be fake?
Well ... remember that TalkTalk has been hacked a few times now, and my information was probably included in the hack. So it's entirely possible that the email is a scam.
An alternative explanation is that TalkTalk is happy to send out emails that look precisely like a scam email.