I have never used sourcemore but I have used CVapor, which is the same company.
Cvapor, and I assume Sourcemore, uses a shipping agent called WanbExpress and their tracking is only good up to the airport lol. From there, no tracking to you door.
However, that package is addressed to another shipping agent in the US who gets notified of the shipment and prints a USPS label within days waiting for the package to come. Once the package arrives, they put that USPS shipping label on the package and it gets delivered to you by USPS.
After you place your order and you get the WanbExpress tracking #, you can email them a few days later to request the USPS tracking #. But it won't show as valid until it actually is received by the US agent, scanned and is in the hands of USPS.
WHAT.A.HASSLE if, like me, you must know when a package is supposed to arrive.
Cigabuy & 3FVape also use Wanb.
Pretty much any vendor that uses "USA Special Line" or similar to describe their US shipping service, instead of "e-packet", is probably using Wanb. You'd know if they are using Wanb because the tracking # starts with WANB. You have to track it using a 3rd party site like 17track.net, not USPS.
I like fasttech better for this reason as their tracking #s are good from their agent to your door. Plus their shipping is cheaper. But their prices are much higher on mods and tanks.
At any rate, they are all the same in the end. You just have to shop around. FT is extremely high for pretty much everything anymore. I use them mainly as a vape parts store and coils. they used to be a great place to buy all vape gear and especially clones, but no more.