what are the options for resigned user, we want to keep users data however if we disable the mailbox all the data will be deleted too. we want to keep mailbox data while delete the mailbox.
I would make it a shared mailbox and remove the license... if you really want to keep the data and delete the mailbox, you'll need to export the mailbox to a pst.
You can also make the mailbox inactive by placing a hold on the mailbox before deleting the owner's Azure AD account. Here's a comparison of inactive versus shared mailboxes as ways to deal with retention of mailbox content for departing employees: https://office365itpros.com/2022/05/31/inactive-mailboxes-shared/
