Follow these steps to set up your Gmail POP Account in Evolution:
Log in to your Gmail account.
Go to Settings ▸ Forwarding and POP/IMAP. Refer to the POP Download section.
Enable the POP download feature by ticking the radio button that corresponds to either of these options:
Enable POP for all mail (even mail that's already been downloaded)
Enable POP for mail that arrives from now on
Specify the other required settings for this Gmail feature.
To know the Gmail Account settings, click on Configuration instructions ▸ Other ▸ Standard Instructions.
On your Evolution client, go to Edit ▸ Preferences ▸ Mail Accounts. Click Add.
Provide the required information. For the account settings, refer to Step 5