MMS are Multi Media SMS, as text messages to which a photo or video can be added. A very cool feature, but in the past it was strongly replaced by WhatsApp.
However, if you want to receive an MMS, you may not receive it, even though you know that the sender sent it.
If this is the case, please try the following trick to receive MMS.
Send an MMS from your Huawei Y5 & Y6. This step is necessary for some mobile providers in order to receive MMS.
Sounds strange, it is, but often this procedure helps to receive MMS on a smartphone like the Huawei Y5 & Y6.