USPS item says it was not sent yet! However seller said it was... Where is my package!?

My package was mailed Priority from the US on March 19 headed for the UK. It's the 26th and the tracking system still says:

Class: Priority Mail International Parcels

Service(s): International Parcels

Status: Electronic Shipping Info Received



The U.S. Postal Service was electronically notified by the shipper on March 18, 2010 to expect your package for mailing. This does not indicate receipt by the USPS or the actual mailing date. Delivery status information will be provided if / when available. Information, if available, is updated periodically throughout the day. Please check again later.



Royal Mail and parcelforce both do not recognize the tracking number. Is my package lost??USPS item says it was not sent yet! However seller said it was... Where is my package!?
If Royal Mail or Parcel Force tracking doesn't recognise the number, you can assume that it hasn't entered their networks. Therefore its still in the States.



From what I can gather, it looks like something has gone wrong before the item actually entered the USPS network - i.e. at the post office you sent from.

It may be that the item has actually entered the network, but for some reason the tracking has malfunctioned. This can happen sometimes.



You know what you've sent so you will know if this is an issue - mail is carried in the hold of passenger airliners, therefore is subject to airport security. If there is anything suspicious or prohibited from flights, it may be held for extra inspection. It may even be rejected from the flight and put in a container for shipping by sea. This may explain any potential delay, although not the discrepancy in the tracking.
They don't track most international priority mail shipments. If the seller used a flat rate envelope it probably won't be tracked at any point, not by USPS and most likely not by your mail service in the UK either.

I am not sure of the delivery estimate for priority international but this doesn't sound like too long of a wait. I doubt its lost, they just didn't update the system.USPS item says it was not sent yet! However seller said it was... Where is my package!?
UK postal service would have no access to USPS tracking numbers - Did sender even USE tracking Number? just sending it Priority mail doesn't mean a confirmation/tracking number was used - that costs extra - it takes awhile to ship things overseas - it's only been 5 business days - no way it would get there this quick - maybe by NEXT Friday
Package stolen by UPS driver who collected it from shipperUSPS item says it was not sent yet! However seller said it was... Where is my package!?
It seems it might not have been sent yet. Shipping info was, but not the actual package.
USPS does not offer tracking on overseas mailings. You will just have to wait for it to arrive.