Hello @asherb05. Depending on how you entered the contacts, you may not receive a welcome email. If a new contact (one that has never been in the account before) was entered in using one of our web sign up methods, such as a sign up form or pop up form, the welcome email will send. However, if the contact was entered by one of the upload methods in the account (like a file upload or by entering a single contact), the welcome email will not send.
If you wish to send a welcome email to all new contacts, not just those that came through an external sign up method, you will need to recreate the welcome email as an automated series that contains the one email.