when will the mail arrive depends on the type of mail service used and the destination of the package. For standard USPS mail, delivery times can range from 1 to 7 business days, depending on the service (e.g., First-Class Mail, Priority Mail). Expedited services like USPS Priority Mail Express offer guaranteed next-day delivery in most areas. For international mail, delivery times can vary greatly, depending on the destination country, customs processing, and the shipping carrier. Tracking information is typically available for most services, allowing customers to monitor the progress of their packages and estimate the delivery date.