After spending about a week and hours each day over 8 programs trying to find a way to migrate my emails off BT business outlook account I've found a solution.
SOLUTION: Download "Thunderbird" email and add "Owl for Exchange" extension and, wallah! All my emails have pulled through. I'll never use BT or Microsoft for business emails ever again.
NOTE: the license for Owl is short and I haven't a clue what happens after so perhaps once the emails have been downloaded transfer over to local folders and export the file and then download exported files in another program.
NOTE: Thunderbird extension "importexport" can be used to export in different formats.
None of the below Imap or pop settings worked along with older settings. I've just noted them for search purposes to find this article.
outlook.office365.com
port 995
SSL applied/ticked
smtp.office365.com
port 587
SMTP authentication applied/ticked
TLS applied/ticked
Authentication - password
and
Server name: outlook.office365.com
Port Number: 993
Encryption: SSL/TLS
2. POP Server Settings
Server name: outlook.office365.com
Port Number: 995
Encryption: SSL/TLS
outlook-out-of-office