Far too simplistic answer which while being true has a lot of gotchas.
It was a simplistic answer because it really is that simple.
Firstly the validation process can take up to five days.
It takes seconds for BT Yahoo to send the email, and another few seconds to click the link and log in.
Secondly the configuration of your email client is by no means straightforward, and more importantly ONLY works when connected to BT. All OK when using a desktop but if it is a laptop, it becomes an absolute disaster as those settings won't work if away from home. So sending out emails from, say, a hotel you are staying in, will fail in 99% of cases.
Completely wrong. BT Yahoo uses authenticated smtp which can be used from any connection, and if the network you are on blocks port 25, then port 587 can be used.
Well all I can say is that we must be living on a parallel universe because my claim to owning a domain name was verified through a manual process and because the whois information contained errors it took time to resolve the matter. Yes going to the web page and answering a few questions takes no time at all but what you are suggesting is verification of the information supplied is an automated process to get a response back so quickly, but I am very sceptical that was the case.
I hope we are on the same hymn sheet and thinking about email clients and not web mail. Do I assume that email forwarding to a BT supplied account is in the equation or hosting facilities are being used as the setup will be different for either case? What is unquestionable is the desire to despatch emails using BTs SMTP server.
The aim should be a set up that will work whether you are connected to BT or another provider. With an email address of say firstname.lastname@example.org
you can use the SMTP server of smtp.btinternet.com in conjunction with authentication using a btinternet.com email address and all is fine. Port 25 with no encryption works but sometimes a different port number may be required. OK, I concede that for most computer users, the setup procedure is relatively simple.
But the same techniques are certainly NOT true where btconnect.com comes into the frame. Complexity rules the day in that environment only to discover that there is NO common configuration to allow [own domain name] emails to pass through
mail.btconnect.com irrespective of the ISP connection made.
The standard setup for a btconnect.com email address would be:
Incoming Mail Server: pop.outlook.com on port 995 with SSL
Outgoing Mail Server: smtp.outlook.com on port 587 with TLS encryption
With your own domain name email address the settings are:
Outgoing Mail Server: mail.btconnect.com with no authentication on port 25 with no encryption.
Twiddling with any combination of settings does not produce a configuration set that will work with BOTH BT or another provider.
So depending on whether you are a btinternet.com or btconnect.com customer makes a difference between something that is relatively straightforward setting up an email client using your own domain name that works irrespective to the ISP you connect to a much more complex setup that doesn't work everywhere.
Everything in the garden is not a bed of roses when BT is your ISP. It may be a pleasure to do a task sometimes quite easily but in some circumstances it is quite demanding and very frustrating. It's that simple.