If you are using a Yahoo or Hotmail address you should change to a Gmail address – better yet – get your firstname.lastname@example.org address. On the other hand if you want to maintain your “old school” image keep on using those old addresses.
By the way – do NOT cancel those old addresses – just start using the new address in current applications.
If your company demands you use their email address it means you will lose all your contacts if you leave or retire. When you move to a new company part of your agreement negotiations should include continuing to use your chosen email address.