Smartphones are an integral part of workflow these days, social media is on rise but email will still take priority when we consider professionalism, this is where you need to try #Outlook.
The default mail clients on #Android have always been lack luster and too slow if you have multiple folders and accounts. Outlook lets you setup multiple accounts with ease and help you sort your mail easily with their focused inbox feature. Lastly they have a builtin calendar app which seamlessly connects with your Inbox and lets you organise your work life easily.
Outlook is great on #iOS also but the default mail app is better integrated with the software due to nature of Apple's ecosystem.
This is a suggestion and not a promotion.