What's the plural form of incorrespondence? Here's the word you're looking for.
Answer
The noun incorrespondence can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be incorrespondence.
However, in more specific contexts, the plural form can also be incorrespondences e.g. in reference to various types of incorrespondences
or a collection of incorrespondences.
Examples
I have been incorrespondence with the council for three years and still nothing has been done.