With the recent heartbleed SSL vulnerability, FastMail have updated their SSL certificates. Here's how to download the certificate and convert it into PEM form.
Find out which certificate you need:
% msmtp -a fastmail --tls-certcheck=off --tls-trust-file= --serverinfo
Download the certificate:
% curl -O https://www.digicert.com/CACerts/DigiCertHighAssuranceCA-3.crt
Convert it into PEM format:
% openssl X509 \
> -inform DER -in DigiCertHighAssuranceCA-3.crt \
> -outform PEM -out DigiCertHighAssuranceCA-3.pem
Thanks for this!
For other readers: It's also possible to skip handling the cert file and instead use the
tls_fingerprint
.