I am using Digitalocean for odoo 12. whenever i get to configure the outgoing email with a gmail email. i get the error

Connection Test Failed! Here is what we got instead:
534
5.7.14 <https://accounts.google.com/signin/continue?sarp=1&scc=1&plt=AKgnsbs5
5.7.14 JMGXXd74oXQUcAG9cpUuk1v6dn8q83DU2xN4q2GA7fl7-h1c0cwvxNJQg6kYvxvtb__RyS
5.7.14 KT04wzdCpiraDSGF2kcjcc2c3jlrDPttHbXb4-jmqDGfyY4912UUARtSA4pfxefOhtbv2C
5.7.14 IYLORL9EhuqgKwoL9rwQgvvbpP6DRIyBpXvEaHvgf0w7n0pJugLwYATp> Please log
5.7.14 in via your web browser and then try again.
5.7.14 Learn more at
5.7.14 https://support.google.com/mail/answer/78754 t3sm4713773pgv.39 - gsmtp