If all you want is an affordable outright purchase for calls and emails then the Poco M3 will last an age and could serve you well. But the quality of even lesser-specified devices out there - which run better overall - means it's not one to recommend.
Very affordable for such a well-rounded specification; Large screen with Full HD+ resolution; Quicker Wi-Fi than some low-price rivals; Massive battery - so lasts for an age
Screen has poor touch response; Often sluggish around user interface; Cameras an oversell (macro and depth not needed); Xiaomi's MIUI 12 software irks; Poor vibration/haptics sensation