server_root_cert_pem_start variable

Root cert for smtp.googlemail.com, taken from server_root_cert.pem The PEM file was extracted from the output of this command: openssl s_client -showcerts -connect smtp.googlemail.com:587 -starttls smtp The CA root cert is the last cert given in the chain of certs. To embed it in the app binary, the PEM file is named in the component.mk COMPONENT_EMBED_TXTFILES variable.