To protect our email server from abuse by spammers, we also require all emails sent through our email service to have SMTP authentication. SSL (Secure Socket Layer) ensures that all data exchanged between your email client and the BT Email server is encrypted making it almost impossible for anyone to steal your username or password.So if you're going to regularly use webmail and an email client, we'd recommend using IMAP with SSL enabled. POP3 doesn’t sync with the BT Email server so changes you make in your email program will not be transferred to your webmail inbox and could be lost.
Look to see whether the Mail Server 'type' is set to IMAP or POP. To find out if you're using IMAP or POP, open up your email program, highlight the mail account you want to find out about, then open its settings or properties. IMAP and POP are the protocols or technologies that enable you to download your email messages to your computer or device.