You've created an email sequence but the status says "failed".
Here are a number of reasons why.
Possible Cause: If you selected your email to be triggered immediately whenever a contact is added manually this is likely to fail.
Reason: Sanity OS has an auto-save facility built in, when creating a record it's saved in real-time even before you've completed it's auto-saving.
Why does this matter?
Well, when you create the trigger and set the email to send immediately (only in this particular instance) the email is literally triggered immediately even before you've had a chance to enter the email address in- impossible right? Exactly, and that's why it fails.
When using email sequences that are triggered when a lead is manually created add a delay of 3-10 minutes (depending on how long it will take you to populate a record). Triggers are sent on every fifth minute so consider this separately from your delay time.
Other possible causes
Another possible cause is that your mailserver settings are invalid or there is a problem with your sending service. Please refer to your sending provider if you cannot send emails.