Go to Settings / Integrations / Email / Click on Configure:

Enter the settings required for your Email SMTP Server:

Default Emails Per Batch - Allows you to throttle back how many emails go out per batch.

Default Seconds Per Batch - Allows you to configure a break between batches.

Copy to All Regions - This will copy these default settings to all Regions.

Set All Notifications to Default Batch - Sets all notifications to the Batch Totals Configured Above (these can be customized for any email)

Gmail - DO NOT CHECK THIS for App Password Configurations, this is only for OAuth Configurations and is significantly more complicate to configure on the Google Side.