Thanks very much to both of you. Just to respond to your questions:
- Yes, e-mails were encrypted to the certificate. To make sure this was the case, I had deleted the old PGP key out of SED altogether (after backing it up) and confirmed I could still read encrypted e-mails that were sent to me.
- I have not attempted to use PGP Zip as I don't use that functionality. However, I have just tried it and it seems to work just fine, encrypting and decrypting, using the certificate and not the old PGP keypair. It shows the Key ID associated with the cert
- I am quite certain that I have imported the private key from the pfx file. When I click on "My Private Keys", it appears there. In addition, I can decrypt, on SED, messages that have been encrypted using the public key associated with the cert, which presumably would not be possible if I had not imported the private key.
- Yes, I used the File, Import Certificate option in SED. The certificate was already imported into the Windows Personal Certificates store.
- I have already imported the pfx into the e-mail encryption app on my phone. I have not imported the pfx into the phone certificate store. Interestingly, while I can send an encrypted e-mail using my phone, which I can then read on Outlook using SED, I can't read an encrypted e-mail on my phone which is sent from Outlook using SED.