diff --git a/README.md b/README.md
index f96e4a7..0759b67 100644
--- a/README.md
+++ b/README.md
@@ -11,16 +11,32 @@ Rationale:
 * Standard-compliant (we don't care about Microsoft Outlook)
 * Fully open-source
 
-## Usage
+## Setup
+
+### Golang
+
+hydroxide is implemented with Go. Head to [Golang website](https://golang.org) 
+for setup information.
+
+### Install and Setup
+
+Install hydroxide
+
+```shell
+go get github.com/emersion/hydroxide/cmd/hydroxide
+```
 
 Your credentials will be stored on disk encrypted with a 32-byte random
 password. When configuring your client, you'll need this password.
 
 ```shell
-go get github.com/emersion/hydroxide
 hydroxide auth <username>
 ```
 
+## Usage
+
+hydroxide can be used in multiple modes.
+
 ### CardDAV
 
 You must setup an HTTPS reverse proxy to forward requests to `hydroxide`.
diff --git a/cmd/hydroxide/hydroxide.go b/cmd/hydroxide/hydroxide.go
index ba9f1b0..2a0eed7 100644
--- a/cmd/hydroxide/hydroxide.go
+++ b/cmd/hydroxide/hydroxide.go
@@ -148,6 +148,7 @@ func main() {
 		s.Addr = "127.0.0.1:" + port
 		s.Domain = "localhost"     // TODO: make this configurable
 		s.AllowInsecureAuth = true // TODO: remove this
+		//s.Debug = os.Stdout
 
 		log.Println("Starting SMTP server at", s.Addr)
 		log.Fatal(s.ListenAndServe())
diff --git a/protonmail/protonmail.go b/protonmail/protonmail.go
index a5a723f..2e17e7c 100644
--- a/protonmail/protonmail.go
+++ b/protonmail/protonmail.go
@@ -4,6 +4,7 @@ package protonmail
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -23,7 +24,8 @@ type resp struct {
 
 func (r *resp) Err() error {
 	if err := r.apiError; err != nil {
-		return r.apiError
+		err.code = r.Code
+		return err
 	}
 	return nil
 }
@@ -33,11 +35,12 @@ type maybeError interface {
 }
 
 type apiError struct {
+	code int // populated by resp
 	Message string `json:"Error"`
 }
 
 func (err apiError) Error() string {
-	return err.Message
+	return fmt.Sprintf("[%v] %v", err.code, err.Message)
 }
 
 // Client is a ProtonMail API client.
diff --git a/smtp/smtp.go b/smtp/smtp.go
index 21ef144..dbeb2bc 100644
--- a/smtp/smtp.go
+++ b/smtp/smtp.go
@@ -237,7 +237,7 @@ func (u *user) Send(from string, to []string, r io.Reader) error {
 
 		if len(resp.Keys) == 0 {
 			plaintextRecipients = append(plaintextRecipients, rcpt.Address)
-			break
+			continue
 		}
 
 		// TODO: only keys with Send == 1