In an effort to fight spam, Google temporarily disables your account if it suspects or detects any unusual activity on your account:
- Sending many emails with a new Gmail or Google Workspace account
Google carefully monitors usage on your account, specifically when it is a new one. Make sure to 'warm' up your account before sending a lot of emails. You can start by first sending a few emails, and only to people you know to avoid your account being blocked by Google.
- Sending a large number of undeliverable messages
If you send content to people you don’t know or to too many people at the same time you will receive many messages that bounce back to your inbox.
Learn more: What are bounces? How to track bounce rate?
If you are a Google Workspace admin, you can unblock an account up to 5 times per year. Find more information: 'Restore a suspended Google Workspace account'
If you have a Gmail account, read this article to know how to restore it.
More information on Google documentation: 'Your account is disabled'