Hi Everibody. I have read that outlook express 5.0 uses both p7b and p7c formats in certificates that it use. I think p7b is the standard format pkcs7, is this correct?. If this is correct, what are differences between p7b and p7c?. How can i make a certificate and private key whith openssl-0.9.5a that outlook express 5.0 take as correct? thanks in advice __________________________________ Mariano Jesus Perez University of Málaga (Spain) Security Group (GYSUM) __________________________________ ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [EMAIL PROTECTED] Automated List Manager [EMAIL PROTECTED]