correspondence
🇺🇸
/ˌkɔːrəˈspɑːndəns/
🇬🇧
/ˌkɒrəˈspɒndəns/
letters, emails, or messages sent and received
I keep all my correspondence in a special folder.
the act of writing letters to someone
Our correspondence helped us stay in touch over the years.
a connection or similarity between two things
There is a clear correspondence between these two ideas.