Create a certificate preference in Keychain Access on Mac
If you communicate via email with someone who uses different certificates for different email addresses, you can create a certificate preference to specify which certificate to use when you email them.
Create a new certificate preference
Go to the Keychain Access app
on your Mac.To open Keychain Access, search for it in Spotlight, then press Return.
Select “login” in the Keychains list.
Select Certificates in the Category list.
Do one of the following:
Select the certificate you want to use and choose File > New Certificate Preference.
Choose File > New Certificate Preference, click the Certificate pop-up menu, then choose the certificate you want to use.
In the Location or Email Address box, enter the location (URL) or the email address for which the certificate is required.
Click Add.
To review the certificate preferences you’ve created, click the Kind column heading while you’re viewing your certificates, then look for “certificate preference” in the Kind column.
Remove a certificate preference
Go to the Keychain Access app
on your Mac.To open Keychain Access, search for it in Spotlight, then press Return.
Select “login” in the Keychains list.
Select All Items in the Category list.
Click the Kind column heading to sort all items by kind, then scroll down until you see your certificate preferences listed.
Select a certificate preference and press Delete, then click Delete.