How does China Unicom receive SMS overseas?

China Unicom's mobile phone needs to meet the following two conditions when sending and receiving short messages abroad:

1. The area visited by users needs international roaming service. If you need to inquire whether the country you are visiting has opened Unicom's international roaming service, you can log in to Unicom's online business hall. Select "outbound roaming" > enter the country you want to query in the country input box > click "search" to query.

2. The mobile phone number needs to be enabled with international roaming function. Open the international roaming function, log in to Unicom's mobile phone business hall with your mobile phone, click Services > Handling > International Hong Kong, Macao and Taiwan Services > Switch roaming services, and select the type to handle.