Need an email app for ios with huge fonts

iOS & iPadOS

since the ongoing problems with dynamic type in the native IOS10 email app, those of us needing very large fonts, due to visual disabilities or circumstances, desperately need a replacement. For those like me needing very large fonts, the IOS accessibility 'pinch' to zoom system is no realistic workaround, as far too much sideways scrolling is needed.
In my case I need an app which can reasonably work with MS Exchange and with Gmail. Essential is that all messages, whether plain-text or HTML-encoded, can be displayed with some kind of a dynamic fontsize definition, with properly wrapped text.
Who has suggestions?