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Choose Tools > Account Settings from the toolbar. Next, you will have to configure Thunderbird to use the certificate with your email account.Click OK to close the Certificate Manager, then close the Options pane. When prompted, enter the password you used when downloading the PKCS#12 file, then click OK.In the Certificate Manager, click Import…, then navigate to the PKCS#12 file you downloaded from SSL.com and click Open.Open Thunderbird, then select Tools > Options from the menu bar.
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However, ECDSA keys cannot be used for email encryption, so it’s best to leave this set to RSA. Note: when downloading your certificate it is possible to choose between the RSA and ECDSA algorithms via the Algorithm drop-down menu.
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