As the title says, I can now send emails as the gmail email I added however the outlook.com account does not receive emails sent to the gmail account, even though it imports the gmail emails at the start of the connection, creating the same folder structure as the gmail account and adding the emails that are already in the inbox.
You have to configure your POP/IMAP settings ( as per your requirements ) in the outlook account settings and enable the same settings in GMail settings.
Here's a link on how to configure outlook account :
Here's another link on how to change POP/IMAP settings ( as what you've selected in outlook ) in GMail :
Go to GMail>settings>POP/IMAP>Enable POP/IMAP.