I need help to find a proper mail archiving solution for a non-profit firm. There are around 6K mails boxes which are yet pending in the database. Now I cannot recommend him to sync the same to their new server where it is of no use. But for future references the mail can be kept archived in some place. I need to provide advice to my friend related to proper solution by which he can reduce the existing mail boxes which are not in usage. I tried to locate some help but many of them are charging at high rates. This is just one time job and I do not think the mails might be needed in future. Any suggestions on this appreciated.