I recently placed my first ever order with any company through attitude seedbank. I had issues with signing for it myself given past history and knowledge. I had attitude send it "NON GUARANTEED" with no t-shirt dvd or anything else...just the original breeder's packs. It arrived in my mailbox without requiring any signature. I didn't sign or talk to the postman, he just left it for me.
On another note though, I did ask the postal office near me if international mail requires a signature....like if its coming from royal mail in england, and it shipped to the usa and came to my house would the USPS require me to sign for it simply because it was international...he told me "most likely". He said its very very common that if its international mail it is processed in USPS as "REGISTERED" mail and that more times than not, USPS considers "REGISTERED" mail as "REQUIRING SIGNATURE" and will make you sign for it regardless of what Royal Mail in England sent it as...
This kind of makes sense if you consider the liability that USPS has when delivering internationally originated mail. If it indeed is from another country,r egardless of whether that country required your signature, USPS might require it just because they want proof that it was indeed delivered to prevent you or royal mail from saying it never got delievered.....so in this way it clears USPS of delivery liability for lost packages.
That all said, my order showed up and didn't require signature...so it seems to be hit or miss, but I hope this info helps you. Ask your local post office about this and see what they say.