Page "Anti-spam techniques" Paragraph 8

Sharing an email address only among a limited group of correspondents is one way to limit spam.

This method relies on the discretion of all members of the group, as disclosing email addresses outside the group circumvents the trust relationship of the group.

For this reason, forwarding messages to recipients who don't know one another should be avoided.

When it is absolutely necessary to forward messages to recipients who don't know one another, it is good practice to list the recipient names all after " bcc :" instead of after " to :".

This practice avoids the scenario where unscrupulous recipients might compile a list of email addresses for spamming purposes.

This practice also reduces the risk of the address being distributed by computers affected with email address harvesting malware.

However, once the privacy of the email address is lost by divulgence, it cannot be regained.