Historically i used Outlook, but in recent months have logged into BT.com to view and send.
I have configured a duplicate account in Outlook and downloaded the contents of the Inbox, but naturally
there is no Sent content. I am looking to download a full content of several email accounts with BT,
to maintain a secure history. Any help appreciated.
You would appear to have set up your email account on Outlook as a POP3 account which does not replicate all the folders on the BT servers.
You need to set up your email client as an IMAP account and that will replicate all the folders that are on the BT servers.
You will then be able to back up the relevant fodders.