diff --git a/options.go b/options.go
index bcf7d29..99e0ef4 100644
--- a/options.go
+++ b/options.go
@@ -103,6 +103,9 @@ func (o *Options) Validate() error {
 	if o.ClientSecret == "" {
 		msgs = append(msgs, "missing setting: client-secret")
 	}
+	if o.AuthenticatedEmailsFile == "" && len(o.EmailDomains) == 0 && o.HtpasswdFile == "" {
+		msgs = append(msgs, "missing setting for email validation: email-domain or authenticated-emails-file required.\n      use email-domain=* to authorize all email addresses")
+	}
 
 	o.redirectUrl, msgs = parseUrl(o.RedirectUrl, "redirect", msgs)
 
diff --git a/options_test.go b/options_test.go
index 8d8fdf8..3b2f19f 100644
--- a/options_test.go
+++ b/options_test.go
@@ -15,6 +15,7 @@ func testOptions() *Options {
 	o.CookieSecret = "foobar"
 	o.ClientID = "bazquux"
 	o.ClientSecret = "xyzzyplugh"
+	o.EmailDomains = []string{"*"}
 	return o
 }
 
@@ -27,6 +28,7 @@ func errorMsg(msgs []string) string {
 
 func TestNewOptions(t *testing.T) {
 	o := NewOptions()
+	o.EmailDomains = []string{"*"}
 	err := o.Validate()
 	assert.NotEqual(t, nil, err)
 
diff --git a/providers/github.go b/providers/github.go
index 4f2a988..c9b490f 100644
--- a/providers/github.go
+++ b/providers/github.go
@@ -2,7 +2,6 @@ package providers
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -66,7 +65,7 @@ func (p *GitHubProvider) hasOrg(accessToken string) (bool, error) {
 
 	endpoint := "https://api.github.com/user/orgs?" + params.Encode()
 	req, _ := http.NewRequest("GET", endpoint, nil)
-	req.Header.Set("Accept", "application/vnd.github.moondragon+json")
+	req.Header.Set("Accept", "application/vnd.github.v3+json")
 	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return false, err
@@ -85,11 +84,16 @@ func (p *GitHubProvider) hasOrg(accessToken string) (bool, error) {
 		return false, err
 	}
 
+	var presentOrgs []string
 	for _, org := range orgs {
 		if p.Org == org.Login {
+			log.Printf("Found Github Organization: %q", org.Login)
 			return true, nil
 		}
+		presentOrgs = append(presentOrgs, org.Login)
 	}
+
+	log.Printf("Missing Organization:%q in %v", p.Org, presentOrgs)
 	return false, nil
 }
 
@@ -111,7 +115,7 @@ func (p *GitHubProvider) hasOrgAndTeam(accessToken string) (bool, error) {
 
 	endpoint := "https://api.github.com/user/teams?" + params.Encode()
 	req, _ := http.NewRequest("GET", endpoint, nil)
-	req.Header.Set("Accept", "application/vnd.github.moondragon+json")
+	req.Header.Set("Accept", "application/vnd.github.v3+json")
 	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return false, err
@@ -130,13 +134,29 @@ func (p *GitHubProvider) hasOrgAndTeam(accessToken string) (bool, error) {
 		return false, fmt.Errorf("%s unmarshaling %s", err, body)
 	}
 
+	var hasOrg bool
+	presentOrgs := make(map[string]bool)
+	var presentTeams []string
 	for _, team := range teams {
+		presentOrgs[team.Org.Login] = true
 		if p.Org == team.Org.Login {
-			if p.Team == "" || p.Team == team.Slug {
+			hasOrg = true
+			if p.Team == team.Slug {
+				log.Printf("Found Github Organization:%q Team:%q (Name:%q)", team.Org.Login, team.Slug, team.Name)
 				return true, nil
 			}
+			presentTeams = append(presentTeams, team.Slug)
 		}
 	}
+	if hasOrg {
+		log.Printf("Missing Team:%q from Org:%q in teams: %v", p.Team, p.Org, presentTeams)
+	} else {
+		var allOrgs []string
+		for org, _ := range presentOrgs {
+			allOrgs = append(allOrgs, org)
+		}
+		log.Printf("Missing Organization:%q in %#v", p.Org, allOrgs)
+	}
 	return false, nil
 }
 
@@ -190,5 +210,5 @@ func (p *GitHubProvider) GetEmailAddress(s *SessionState) (string, error) {
 		}
 	}
 
-	return "", errors.New("no email address found")
+	return "", nil
 }
diff --git a/providers/linkedin.go b/providers/linkedin.go
index 78ad3c9..2151229 100644
--- a/providers/linkedin.go
+++ b/providers/linkedin.go
@@ -3,7 +3,6 @@ package providers
 import (
 	"errors"
 	"fmt"
-	"log"
 	"net/http"
 	"net/url"
 
@@ -60,13 +59,11 @@ func (p *LinkedInProvider) GetEmailAddress(s *SessionState) (string, error) {
 
 	json, err := api.Request(req)
 	if err != nil {
-		log.Printf("failed making request %s", err)
 		return "", err
 	}
 
 	email, err := json.String()
 	if err != nil {
-		log.Printf("failed making request %s", err)
 		return "", err
 	}
 	return email, nil
diff --git a/validator.go b/validator.go
index 396e605..e3c0a54 100644
--- a/validator.go
+++ b/validator.go
@@ -71,9 +71,11 @@ func newValidatorImpl(domains []string, usersFile string,
 		domains[i] = fmt.Sprintf("@%s", strings.ToLower(domain))
 	}
 
-	validator := func(email string) bool {
+	validator := func(email string) (valid bool) {
+		if email == "" {
+			return
+		}
 		email = strings.ToLower(email)
-		valid := false
 		for _, domain := range domains {
 			valid = valid || strings.HasSuffix(email, domain)
 		}