EDIT: This probably applies to all Apple devices, not just the older ones. Hi, does anyone notice problems with lets encryp on older apple devices? Alternatively, how to solve it? They see the certificate, but they consider it untrustworthy. It can affect that openssl writes: verify error: num = 20: unable to get local issuer certificate verify error: num = 21: unable to verify the first certificate Verify return code: 21 (unable to verify the first certificate) Thanks so much for the advice.
How old? It may be it does not have trust for new certificate authorities or their signing. If you have checked with ssl checker (website, find using Internet Search Engines) certificate is OK but you device does not accept it this may be the case.,
Take a look at the postfix and dovecot config to see if the SSL certificate chain is configured there. If that#s missing, then it might be that older services are not able to verify the validity of an LE cert.