0 to send someone a copy of an email that you are sending to someone else:
I'll copy you in on all emails relating to the project.
1 to send someone a copy of an email you are sending to someone else:
copy sb in on sth Be sure to copy me in on all correspondence.
NIEUWE WOORDEN
European
May 10, 2021
WOORD VAN DE DAG
Shimmer
copy sb in