Hello @RudderA ,
We apologize that there was a sending delay for you yesterday evening. With newer accounts, our system will usually spend some extra time processing their first few sendouts to monitor for prohibited content, spam/scams, recognized phishing images / wording / links, etc. It's a proactive measure developed to ensure sending reputations for our company and our customers is maintained, and deliverability remains high. The delayed send time will typically be displayed on the reporting page that is displayed after scheduling. This tells you what the earliest time the campaign will start sending is.
If you have any additional questions, or need any further clarifications, just let us know. Have a good day!