Blockport does not support Ethereum transactions generated from smart contracts (yet). ETH should therefore only be sent through traditional transactions.
If you are uncertain whether the sender uses Smart Contracts, contact them and check. Furthermore, you can always set up a local wallet (ledger, MyEtherWallet) and use this to receive the funds from a smart contract transaction and then send your ETH to your Blockport account.
Users are not able to send or receive ETH from one Blockport account to another