Beginning February 2024, Gmail and Yahoo will require a custom authentication and a published Domain-based Message Authentication, Reporting & Conformance (DMARC) record for anyone sending more than 5,000 emails to Gmail or Yahoo addresses in a 24-hour period. To prevent your emails from bouncing, we strongly recommend authenticating your email domain and configuring DMARC.

Also, if you use a free email service like Gmail or Yahoo for your From email address, we strongly recommend you switch to an email address from a private domain, like the one you use for work or for your website.