Thank you for reaching out to the Community! Can you please provide us with a screenshot of the error message so we can do additional research on why this might be happening? Thanks!
Hello @SteveV310 ,
When you send a test email, it doesn't have the same authentication as a regular, live sendout through our system, which can cause some email clients' algorithms to warn you. Additionally, email clients will typically warn you if an email claiming to be sent to you from you, is actually coming from another source like us.