Thank you for reaching out to the Community! I apologize for the inconvenience, but in a trial subscription you are only able to send to 100 contacts at a time or less. If your list contains more than 100 email addresses it will be grayed out on the scheduling page. I recommend upgrading your account so you can send to as many contacts as you want!
Zoe_H Community & Social Media Support
Did I answer your question? If so, please mark my post as an "Accepted Solution" by clicking the Accept as Solution button in the bottom right hand corner of this post.