But he did invent email.
But what he created is distinct and in no way related or had influence on the design or implementation of email we use today.
The history of email is documented in RFCs that date back to when this supposed 'inventor' was a toddler.
But words are not these neat bundles of data like JSON or XML. They mean different things to different people.
Once mud has been thrown on an argument and everything is see because of the murky grey areas pulling out a dictionary won't help. The other side will just pull out one with a definition that meets their needs.