If the credit card is blocked during the mailing process, it means that the credit card has been sealed in the registered mail or express mail and has been sent.

Sending of postal mail. After sorting (categorizing) the goods or documents that need to be mailed according to destination, item type, size and other standards, several items of the same category are repackaged in a large mail bag and sealed, and then transported and sent.

Goods in the same large mail bag are not separated during transportation. Similar to computer applications, file compression software can be used to compress several files into one file (compressed package) and then transmit the data. The encapsulation process can be compared to the compression and packaging process.