My work email is being deactivated. My laptop is a Macintosh.
You need to use a third-party email client and get your messages via the POP and/or IMAP protocols. A desktop client is usually assumed, but you might be able to use a webmail app like Outlook.com. (You'll have a lot less control of your data with the latter.)
Escaping from Gmail
IMAP, POP Access
It's easy to use a different email reading program with Gmail using either IMAP or POP, or to get all your mail out to take to a different provider. Go to the Settings page (link at top right of Gmail page), Forwarding and POP/IMAP tab.
This tab lets you set up POP and IMAP, with instructions for popular email reading programs. There is extensive online help available for both POP and IMAP. And in case you are not familiar with the difference between POP and IMAP, here's a simple chart:
You will need to download all of your emails using an email client such as Mail on the Mac. Instructions on doing so can be found here