Address bok and multiple emails per user

Hi cubes,

We are in the process of migrating some 20.000 users of openwebmail to RoundCube. So far it has been painless, but now we have stumled across a problem. Openwebmail allowed address book entrys to have more than one email address associated, enabling users to send to groups of people. This is not possible in RoundCube and poses a major set-back for us. Does any one have any ideas how to circomvent this problem?

Another possibility would be to be able to create multipe address books and mail all users in a book, but this also does not seem to be an option?