https://developers.brevo.com/reference/send-test-email
Send an email campaign to your test list | Brevo API Documentation
Send a test version of an email campaign to specified email addresses or your entire test list.
send an email campaigntest list
https://www.gmass.co/
GMass: Easiest way to send an email campaign
GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!
send an emailway togmasseasiestcampaign