If your live.com accounts are IMAP in Outlook, simply add them to TB by clicking the 3-bar menu icon at the upper right, New Account, Existing Mail. Use these settings: incoming IMAP outlook.office365.com, 993, SSL/TLS, OAuth2, email address; outgoing smtp.office365.com, 587, STARTTLS, OAuth2, email address. POP account are the same except incoming port 995. If you have local mail in Outlook, it can be transferred to TB, but the method is a bit more involved. Network calendars and contacts can also be added, and local address books imported.

Thank you for this, actually none of the email addresses are live.com, a number are gmail email addresses and then I have a number which are hosted by my different business domains (either through ionos or others) which have all been pulling into the one place...I'm assuming the above wouldn't work for all these. Apologies as while I can do a bit, I'm not the most technical person. Thank you for all your help

Gmail accounts can be added with the automatic settings in the account setup, but domain accounts usually require manual configuration, e.g. for Ionos. An important requirement with multiple accounts is to ensure they all connect to the correct smtp servers.

If you prefer to show all accounts in a single folder, TB has a Unified Folders view.