Outlook conflict with older version

Hi maursie,

you can use these steps (options):

1. Data Backup:
   Start by backing up all your data in Office 2010, including your address book, POP and IMAP settings, and more.
   Export emails, contacts, and calendar items to Outlook using a .pst file - Microsoft Support

2. Import to Office 365:
   After securing your backup, proceed to import the data into Office 365.
   Export emails, contacts, and calendar items to Outlook using a .pst file - Microsoft Support

3. Account Configuration:
   If you are setting up Outlook 365 on a new machine, you will need to configure each account again. For POP accounts, ensure to copy the associated PST file to the new machine and use it for the account configuration instead of letting Outlook create a new one.

4. Default Account Setting:
   If you have multiple accounts, the order in which you configure them matters. The data file associated with the first email account becomes the default data file for the profile. If you have both POP and IMAP accounts, it's advisable to configure the POP account first and then the IMAP accounts.
   Change the account used to send email messages - Microsoft Support
   Migrating from Outlook 2010 to Office 365 Outlook - Microsoft Community