Lotus Notes security
Lotus Notes is not free, and, until version 5.x, had a tough to navigate, user interface. All this has been changed and Lotus Notes, at the present,v ersion 7.x, is a fully featured, easy to use email client with a lot of different features. Though I will only focus on one feature here, security.
Notes was the first widely adopted program to use public key cryptography for client-server and server-server authentication and for encryption of data, and it remains the product with the largest installed base of PKI users. Until US laws regulating encryption were changed in 2000. Prohibiting the export of encryption products with keys longer then 40 bits. After striking a deal they could export a 64bit encryption. Lotus negotiated an agreement with the NSA that allowed export of a version that supported stronger keys with 64 bits, but 24 of the bits were encrypted with a special key the NSA can decypher quickly. So strong encryption is used, but the NSA can more easily decypher those emails.
There are currently no holes reported for Notes 7.x though 6.x has 1 unpatched rated a medium security risk