CURLOPT_MAIL_FROM - SMTP sender address
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_MAIL_FROM, char *from);
Pass a pointer to a zero terminated string as parameter. This should be used to
specify the sender's email address when sending SMTP mail with libcurl.
An originator email address should be specified with angled brackets (<>)
around it, which if not specified will be added automatically.
If this parameter is not specified then an empty address will be sent to the
mail server which may cause the email to be rejected.
The application does not have to keep the string around after setting this
CURL *curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_URL, "smtp://example.com/");
curl_easy_setopt(curl, CURLOPT_MAIL_FROM, "firstname.lastname@example.org");
ret = curl_easy_perform(curl);
Added in 7.20.0
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or
CURLE_OUT_OF_MEMORY if there was insufficient heap space.