I also bought a few parts from Serverparts and they actually arrived. As my friend wrote, you pay by card, but that's normal.i have recently purchased a X13SEI-F at serverparts.pl ( ITCare-official Supermicro Distributor ). you have to pay with bank transfer, but they are serious.
slow delivery because it comes from SM to poland and from there to you.
email to serverparts.pl <info@supermicro.com.pl>
Bizserver also has Supermicro products - it is also the official distributor of the Supermicro brand in Poland. They sometimes have lower prices than other distributors. The store is in English, payments like everywhere else.