The “Mailed” tracking event is USPS’s confirmation that they have custody of the mailpiece. You can utilize this tracking event to monitor Lob’s SLA adherence and also provide auditable proof and time of mailing.
The “Mailed” tracking event appears at earliest two business days after sending your Lob API request. In some instances, it can take longer for this “Mailed” event to become visible, but when surfaced, it will accurately reflect the actual date of mail handoff to the USPS.
Please note that trackings are not guaranteed by USPS, though we typically receive trackings on over 98% of our mailings.