Specific authors for Mail, the /e/ fork of K9-Mail:
© 2018-2019 - Author: Nihar Thakkar
© ECORP SAS 2018-2020 - Author: Romain Hunault, Alexandre Roux, Mohit Mali

Note: original K9-mail are not listed here. 
Please refer to the source code an/or to the commit history for the complete list of authors.