Printful will cover a variety of courier errors such as lost or damaged in transit, postage due errors or generally misrouted packages when tracking provides no clear details or cause.
In the rare cases that a parcel is marked as delivered by the courier, but the recipient reports they have yet to receive it - Printful would not cover the cost of reshipping the order. Again, this only applies if the tracking details state that a delivery was made to the recipients address.
In most instances, it is found that the delivery was made, but left in an unexpected location at a recipient's address. Recipients should reach out to the courier and inquire if any additional details were left by the delivery person - e.g. "left under table on back porch."
If your customer is unable to locate the package you will need to place a new manual order to have it reshipped. We're not yet able to assist with filing claims with shipping carriers but hope to do so in the future!