You can do this with the "Archive Mail" feature in MailScanner.
1. Create a rules file in /usr/mailscanner/etc/rules. Call it, for example, archive.rules
2. In that file, add a line like the following examples for each domain/address that you want to copy all mails for:
# If you want to copy all mail going into a
# particular domain to a specific mailbox
To: *@domain1.com firstname.lastname@example.org
# If you want to copy all mail to or from a certain
# account to another mailbox
ToOrFrom: email@example.com firstname.lastname@example.org
Adjust as needed to accomplish what you want. There is no need to include a default line.
3. In WHM - ConfigServer MailScanner FE - MailScanner Configuration, search for "Archive Mail =". Enter the following value:
(or whatever you called your rules file)
Click Change to save the changes and restart MailScanner.Note:
You should ensure that you are familiar with and comply with your country's privacy laws before setting up mail archiving.