"Syncing with Gmail is the hardest part to set up in Evolution,
but it's not that hard. First, enable IMAP in Gmail. Then open
Evolution, go to Edit -> Preferences -> Mail Accounts, and
click on the Add button. In the resulting wizard, enter your name,
email address, and (optionally) your reply-to and organization. At
the next screen of options for setting up email reception, change
the server type to IMAP and put imap.gmail.com in the Server field.
Enter your email address as your username, change Secure Connection
to SSL, and change the Authentication Type to Password. Optionally,
you can check Remember Password.
"On the screen where you set up sending email, change the Server
Type to SMTP, enter smtp.gmail.com in the Server box, check Server
requires authentication, Secure Connection to TLS, Authentication
to Login, and username to your email. Optionally, you can check
Remember Password. Name your account and click Apply. You should
see your new Gmail inbox under accountname/Inbox (not the On This
Computer inbox) in the lefthand sidebar. Most of your Gmail folders
will show up as subfolders under accountname/[Gmail], including All
Mail (Archive), Drafts, Sent Mail, Spam, Starred, and Trash. Your
labels should show up as a folder under ACCOUNTNAME."