I have two new Windows 8.1 computers running Office 365 and I have two older home computers running windows live mail 2012. I want to move the mail and accounts across to the new platforms. WLM has an export function for the messages and accounts. However I cannot export as an exchange pst from the old machine, because it searches for outlook on the old computer and it's obviously only installed on the new computers. Outlook 365 does not appear to have an import function for anything other than a pst. WLM will export account information to an .iaf file, but outlook 365 does not appear to have an import function. Can anyone advise how to migrate from WLM 2012 to Outlook 365. Both computers have very large archives of mail which must be retained. 

Is the only way to achieve this; Install WLM on the new machines and delete after use?