
An official announcement is expected at IBM's Lotusphere 2008 conference in Orlando this week.
The software, which requires use of IBM's Domino email server, will offer iPhone users access to standard Notes tools, including email, calendar and databases.
Users with a Lotus web-access licence will get the software for free, while pricing for new users will start at US$39 per year.
iPhone users can already connect to web-based email services such as Gmail, as well as corporate email sent over Microsoft Exchange.
IBM claims 135 million Lotus Notes users worldwide.