There are several tools and methods you can use to perform client previews:
Manual Testing: Send test emails to different email accounts you control, such as Gmail, Yahoo, and Outlook. Check how the email looks on both desktop and mobile. Email Testing Tools: Tools like Litmus, Email on Acid, and Mailtrap can automate the process and provide screenshots of how your email will appear across various clients and devices. Browser Extensions: Some browser extensions can also help you preview emails in different clients without leaving your email marketing platform.