Santa Clara, Calif.--Mailshell.com, an e-mail privacy company, has introduced a software package that blocks unsolicited messages from b-to-b lists. Such software packages geared toward consumers are common; b-to-b versions are rare. It will reject incoming e-mails with foreign code, allowing execs to avoid spam. Subscribers also will be able to enlist in special-interest opt-in e-mail programs. Corporate concern regarding unsolicited e-mails is on the rise as the volume of b-to-b e-mail marketing campaigns mushrooms.