Hello A couple of months ago I started to use smime, with epg, gpgsm (certificates from comodo). I had no problems interchanging encrypted and signed message with users of thunderbird (seamonkey), evolution, kmail and applemail. However I do have problems with users of outlook 2003/2010 (and these users cannot change their mail program). So I installed outlook 2003 in a virtualbox and indeed (after having installed the certificates and interchange signed message) I receive the following error message when opening an encrypted+signed message sent by xemacs: "Your Digital ID name cannot be found in the underlying security system" So I thought this is outlook's fault. But then I tried out thunderbird, and outlook has no problems opening a signed+encrypted message. Then I tried out kmail, which also uses gpgsm, and again outlook can open the signed+encrypted message. So I am really puzzled. I saved the 3 messages - thunderbird - xemacs - kmail In thunderbird .eml format and attach them below. The difference between kmail and xemacs is very subtle, but I fail to see any deeper reason. Any suggestion is very welcome. thanks Uwe Brauer Uwe Brauer