FWIW, the two main online chess sites forbid the use of engines in correspondence games. But both do allow the use of opening databases.
(https://www.chess.com/terms/correspondence-chess#problems, https://lichess.org/faq#correspondence)
https://www.iccf.com/ allows computer assistance
FWIW, the two main online chess sites forbid the use of engines in correspondence games. But both do allow the use of opening databases.
(https://www.chess.com/terms/correspondence-chess#problems, https://lichess.org/faq#correspondence)
https://www.iccf.com/ allows computer assistance