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If I check my voice mail while abroad and iam in wifi will I be charged yes or no
In order to prevent unintended roaming charges, it is generally recommended to disable data and roaming data. However, you should note that disabling those settings does not prevent roaming for voice and messaging. In addition, some manufacturers might allow some data usage to occur despite those settings (see here). That's why it is also generally recommended to enable Airplane and/or Flight modes in order to prevent unintended roaming usage. You could then manually enable Wifi when required.
Merely connecting to Wifi for regular internet usage would not allow for calling and messaging so any usage would be over the cellular networks and incur roaming charges (assuming Airplane and/or Flight mode disabled). However, if your plan and device are supported for Wifi-calling, your device would be connected to the network via their internet gateway (see image here). As such, using Wifi-calling is technically using Fido services. However, they have allowed certain usage to be free from additional charges. All the messages and calls you receive (from anywhere in the world) will be taken from your plan's voice minutes and messaging limits. As well, all Wifi-calling messages and calls you make to a Canadian phone number while abroad won't incur long-distance or roaming charges (see link above).
Since checking your voicemail would entail calling a Canadian phone number, you should not incur roaming charges for checking your voicemail with Wifi-calling. You would need to ensure your device is connected via Wifi-calling, though. Most devices would have a Wifi-calling icon when connected. Wifi-calling can be used with Airplane mode enabled and cellular data disabled to prevent unintended usage over cellular networks.
Hope this helps 😀