While gmail is probably the most popular email provider, there have been some changes that make it harder to set up emails on some items - a prime example being your website. Some users report only being able to get a business email account managed by gmail to work by paying for the G-suite. Try this first though:
In Google Mail, you must allow "less secure" apps access in order for your SMTP settings to work. There are two places this setting must be enabled:
Once enabled in both places, you're good to go!
Please note that these options are not available if you have two-factor authentication (2FA) enabled for your Google account. Instead of using SMTP, you will need to generate an app password if you are using 2FA. Google has a guide for that here: https://support.google.com/mail/answer/185833?hl=en-GB
