Allow BCC emails to be forwarded to multiple groups

[stewrg]

Occasionally there is a requirement to send the same email to two or more groups. Currently Trident only forwards to one of the email addresses in a CC line (which is probably a security feature to prevent accidentally showing two groups the existence of the other.

However, where the emails are in a BCC list sent by somebody with rights to send to both groups, the email should be forwarded.

Note: It seems to forward to the first email address based alphabetically - and doesn't send to any other listed in a BCC field.