Mail-It was Unipalm's own email client. Our principle supplier Ftp software Inc. was late in identifying that the migration from MS-DOS to Windows. Their refusal to prioritise an Email client resulted in my deciding to write own own.
Mail-It was designed to use industry standard API "MAPI". Our product was so good it was bought by Microsoft for $1m.
However, we failed in the retail marketplace, due to a viral sales campaign by Eudora. The first version of Eudora was given away, while limited in features it was better than most Windows Email clients. They then offered Eudora Pro, a full featured email client for a modest upgrade fee. This was my second experience of being on the receiving end of "viral marketing".