$17 per year to have a stable custom domain for your Gmail address

0 What I have?

• a free gmail account jinqiangzhao2017@gmail.com
• a domain name "linuxexam.net" registered with Google Domains for $17 per year.

1 What is the goal?

• When someone sends emails to jonathan@linuxexam.net, those emails will be delivered to my Gmail account.

• When I send out emails on Gmail, I am able to select sending it from jonathan@linuxexam.net. So the recipients will see the sender too.

• As a result, I have a fully working custom domain email account, while this account actually is an alias to my existing google account.

2 Configure email forwarding 

2.1 configure "email forwarding" on Google Domains pannel

[Google Domains]  [Email] [Email forwarding]

At this moment, I should already be able to receive mails sent to jonathan@linuxexam.net.

2.2 Verify

Verify that emails sent to "jonathan@linuxeam.net" can be delivered to my Gmail account Inbox.

But I am not able to send emails as jonathan@linuxexam.net yet.

3 Configure sending email as

3.1 configure "Send email as" on Gmail account settings

[Settings] [Accounts and Import] [Send email as:]

Make sure "Treat as an alias" is checked.

Pleate be noted that here 

• the SMTP server is "smtp.gmail.com"
• Username is Gmail account "jinqiangzhao2017@gmail.com"
• Password is NOT Gmail account's password, but a App password.

3.2 Generate an App password on Google account security

Generate an App password for "Mail", and remember it.

Use this password to finish the last step in 3.1.

3.3 verify

Now, when composing a new email on Gmail, it will let you select from the custom domain email.

The recepient can see it indeed came from my jonathan@linuxeam.net.