MUL-4460: fix(email): add SMTP_FROM_EMAIL for SMTP sender

Closes MUL-4460
2026-07-26 20:45:37 +02:00 · 2026-07-14 14:26:16 +08:00
parent 6c6143e8fc
commit 5b57a8ebca
7 changed files with 104 additions and 11 deletions
--- a/.env.example
+++ b/.env.example
@@ -128,6 +128,8 @@ RESEND_FROM_EMAIL=noreply@multica.ai
 # Option B: SMTP relay (for self-hosted / on-premise deployments)
 #   Takes priority over Resend when SMTP_HOST is set.
 #   Supports unauthenticated relay (leave SMTP_USERNAME empty) and authenticated SMTP.
+#   SMTP_FROM_EMAIL is the envelope/header sender for SMTP. If unset, SMTP
+#     falls back to RESEND_FROM_EMAIL for backwards compatibility.
 #   Set SMTP_TLS_INSECURE=true only for private CA or self-signed certificates.
 #   SMTP_TLS controls the TLS mode:
 #     - unset / "starttls" (default): plaintext connect, upgrade via STARTTLS.
@@ -142,6 +144,7 @@ SMTP_HOST=
 SMTP_PORT=25
 SMTP_USERNAME=
 SMTP_PASSWORD=
+SMTP_FROM_EMAIL=
 SMTP_TLS_INSECURE=false
 SMTP_TLS=
 SMTP_EHLO_NAME=
--- a/apps/docs/content/docs/environment-variables.ja.mdx
+++ b/apps/docs/content/docs/environment-variables.ja.mdx
@@ -42,7 +42,7 @@ Multica は 2 つの配信バックエンドをサポートします — クラ
 | 変数 | デフォルト | 説明 |
 |---|---|---|
 | `RESEND_API_KEY` | 空 | Resend API key |
-| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | 送信元アドレス（Resend アカウントで検証済みのドメインである必要があり、SMTP を使用する場合も `From:` ヘッダーとして再利用されます） |
+| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | Resend の送信元アドレス（Resend アカウントで検証済みのドメインである必要があります）。`SMTP_FROM_EMAIL` が未設定の場合、SMTP でも使われます |

 ### SMTP relay

@@ -52,6 +52,7 @@ Multica は 2 つの配信バックエンドをサポートします — クラ
 | `SMTP_PORT` | `25` | SMTP ポート。STARTTLS サブミッションには `587` を、SMTPS（暗黙的 TLS、自動有効化）には `465` を使用します |
 | `SMTP_USERNAME` | 空 | SMTP ユーザー名。認証なしの relay の場合は空のままにしてください |
 | `SMTP_PASSWORD` | 空 | SMTP パスワード |
+| `SMTP_FROM_EMAIL` | 空 | SMTP の `MAIL FROM` と `From:` に使う送信元アドレス。未設定の場合は `RESEND_FROM_EMAIL` にフォールバックします |
 | `SMTP_TLS` | `starttls` | TLS モード。`implicit`（別名 `smtps`、`ssl`）は接続時に即座に TLS ハンドシェイクを行います（SMTPS）。`465` ポートでは自動的に有効になります。未設定 / `starttls` の場合は接続後に STARTTLS でアップグレードします |
 | `SMTP_TLS_INSECURE` | `false` | TLS 証明書の検証をスキップするには `true` に設定（プライベート CA / 自己署名証明書のみ） |
 | `SMTP_EHLO_NAME` | マシンのホスト名 | relay に通知する EHLO/HELO 名。厳格な relay（例: Google Workspace `smtp-relay.gmail.com`）が公開 IP からのデフォルトの挨拶を拒否する場合は、実際の FQDN を設定してください — そうしないと relay が接続を切断し、後続のコマンドで不明瞭な `EOF` として表面化します |
--- a/apps/docs/content/docs/environment-variables.ko.mdx
+++ b/apps/docs/content/docs/environment-variables.ko.mdx
@@ -42,7 +42,7 @@ Multica는 두 가지 전송 백엔드를 지원합니다 — 클라우드 배
 | 변수 | 기본값 | 설명 |
 |---|---|---|
 | `RESEND_API_KEY` | 비어 있음 | Resend API key |
-| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | 발신 주소 (Resend 계정에서 검증된 도메인이어야 하며, SMTP를 사용할 때도 `From:` 헤더로 재사용됨) |
+| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | Resend 발신 주소(Resend 계정에서 검증된 도메인이어야 함). `SMTP_FROM_EMAIL`이 비어 있으면 SMTP에서도 사용됩니다 |

 ### SMTP relay

@@ -52,6 +52,7 @@ Multica는 두 가지 전송 백엔드를 지원합니다 — 클라우드 배
 | `SMTP_PORT` | `25` | SMTP 포트. STARTTLS 제출에는 `587`을, SMTPS(암묵적 TLS, 자동 활성화)에는 `465`를 사용하세요 |
 | `SMTP_USERNAME` | 비어 있음 | SMTP 사용자명. 인증 없는 relay의 경우 비워 두세요 |
 | `SMTP_PASSWORD` | 비어 있음 | SMTP 비밀번호 |
+| `SMTP_FROM_EMAIL` | 비어 있음 | SMTP `MAIL FROM` 및 `From:`에 사용할 발신 주소. 설정하지 않으면 `RESEND_FROM_EMAIL`로 대체됩니다 |
 | `SMTP_TLS` | `starttls` | TLS 모드. `implicit`(별칭 `smtps`, `ssl`)은 연결 시 즉시 TLS 핸드셰이크를 수행합니다(SMTPS). `465` 포트에서는 자동으로 활성화됩니다. 미설정 / `starttls`는 연결 후 STARTTLS로 업그레이드합니다 |
 | `SMTP_TLS_INSECURE` | `false` | TLS 인증서 검증을 건너뛰려면 `true`로 설정 (사설 CA / 자체 서명 인증서만 해당) |
 | `SMTP_EHLO_NAME` | 머신 호스트명 | relay에 알리는 EHLO/HELO 이름. 엄격한 relay(예: Google Workspace `smtp-relay.gmail.com`)가 공개 IP에서 보내는 기본 greeting을 거부하는 경우 실제 FQDN을 설정하세요 — 그렇지 않으면 relay가 연결을 끊고, 이는 이후 명령에서 불투명한 `EOF`로 나타납니다 |
--- a/apps/docs/content/docs/environment-variables.mdx
+++ b/apps/docs/content/docs/environment-variables.mdx
@@ -42,7 +42,7 @@ Multica supports two delivery backends — [Resend](https://resend.com/) for clo
 | Variable | Default | Description |
 |---|---|---|
 | `RESEND_API_KEY` | empty | Resend API key |
-| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | Sender address (must be a domain verified in your Resend account; also reused as the `From:` header when SMTP is in use) |
+| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | Sender address for Resend (must be a domain verified in your Resend account). SMTP also uses it when `SMTP_FROM_EMAIL` is unset |

 ### SMTP relay

@@ -52,6 +52,7 @@ Multica supports two delivery backends — [Resend](https://resend.com/) for clo
 | `SMTP_PORT` | `25` | SMTP port. Use `587` for STARTTLS submission, or `465` for SMTPS (implicit TLS, auto-enabled) |
 | `SMTP_USERNAME` | empty | SMTP username. Leave empty for unauthenticated relay |
 | `SMTP_PASSWORD` | empty | SMTP password |
+| `SMTP_FROM_EMAIL` | empty | Sender address for SMTP `MAIL FROM` and `From:`. Falls back to `RESEND_FROM_EMAIL` when unset |
 | `SMTP_TLS` | `starttls` | TLS mode. `implicit` (aliases `smtps`, `ssl`) forces an immediate TLS handshake on connect (SMTPS); port `465` auto-enables it. Unset / `starttls` upgrades via STARTTLS after connect |
 | `SMTP_TLS_INSECURE` | `false` | Set `true` to skip TLS certificate verification (private CA / self-signed only) |
 | `SMTP_EHLO_NAME` | machine hostname | EHLO/HELO name announced to the relay. Set a real FQDN when a strict relay (e.g. Google Workspace `smtp-relay.gmail.com`) rejects the default greeting from a public IP — otherwise the relay drops the connection and it surfaces as an opaque `EOF` on a later command |
--- a/apps/docs/content/docs/environment-variables.zh.mdx
+++ b/apps/docs/content/docs/environment-variables.zh.mdx
@@ -42,7 +42,7 @@ Multica 支持两种邮件发送通道——[Resend](https://resend.com/) 适合
 | 环境变量 | 默认值 | 说明 |
 |---|---|---|
 | `RESEND_API_KEY` | 空 | Resend API key |
-| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | 发件地址（必须是 Resend 账号已验证的域名；走 SMTP 时同时作为 `From:` 头）|
+| `RESEND_FROM_EMAIL` | `noreply@multica.ai` | Resend 发件地址（必须是 Resend 账号已验证的域名；`SMTP_FROM_EMAIL` 未设置时，SMTP 也会使用它）|

 ### SMTP relay

@@ -52,6 +52,7 @@ Multica 支持两种邮件发送通道——[Resend](https://resend.com/) 适合
 | `SMTP_PORT` | `25` | SMTP 端口。STARTTLS 提交端口用 `587`；SMTPS（隐式 TLS，自动启用）用 `465` |
 | `SMTP_USERNAME` | 空 | SMTP 用户名。留空表示未认证 relay |
 | `SMTP_PASSWORD` | 空 | SMTP 密码 |
+| `SMTP_FROM_EMAIL` | 空 | SMTP 的 `MAIL FROM` 和 `From:` 发件地址。未设置时回退到 `RESEND_FROM_EMAIL` |
 | `SMTP_TLS` | `starttls` | TLS 模式。`implicit`（别名 `smtps`、`ssl`）在连接时立即进行 TLS 握手（SMTPS）；`465` 端口会自动启用。未设置 / `starttls` 则在连接后通过 STARTTLS 升级 |
 | `SMTP_TLS_INSECURE` | `false` | 设为 `true` 跳过 TLS 证书校验（仅限私有 CA / 自签证书）|
 | `SMTP_EHLO_NAME` | 机器主机名 | 向 relay 通告的 EHLO/HELO 名称。当严格的 relay（例如 Google Workspace `smtp-relay.gmail.com`）拒绝来自公网 IP 的默认问候时，填一个真实的 FQDN——否则 relay 会直接断开连接，并在后续某条命令上表现为一个不知所云的 `EOF` |
--- a/server/internal/service/email.go
+++ b/server/internal/service/email.go
@@ -111,6 +111,20 @@ func smtpAuthWithFallback(c smtpAuthClient, host, username, password string) (bo
 	return true, plainErr
 }

+func resolveFromEmail(smtpHost string) string {
+	resendFrom := strings.TrimSpace(os.Getenv("RESEND_FROM_EMAIL"))
+	if smtpHost == "" {
+		if resendFrom != "" {
+			return resendFrom
+		}
+		return "noreply@multica.ai"
+	}
+	if smtpFrom := strings.TrimSpace(os.Getenv("SMTP_FROM_EMAIL")); smtpFrom != "" {
+		return smtpFrom
+	}
+	return resendFrom
+}
+
 func (s *EmailService) openSMTPClient() (*smtp.Client, error) {
 	addr := net.JoinHostPort(s.smtpHost, s.smtpPort)

@@ -162,11 +176,6 @@ func (s *EmailService) openSMTPClient() (*smtp.Client, error) {

 func NewEmailService() *EmailService {
 	apiKey := os.Getenv("RESEND_API_KEY")
-	from := strings.TrimSpace(os.Getenv("RESEND_FROM_EMAIL"))
-	if from == "" {
-		from = "noreply@multica.ai"
-	}
-
 	smtpHost := strings.TrimSpace(os.Getenv("SMTP_HOST"))
 	smtpPort := strings.TrimSpace(os.Getenv("SMTP_PORT"))
 	if smtpPort == "" {
@@ -175,6 +184,7 @@ func NewEmailService() *EmailService {
 	smtpUsername := os.Getenv("SMTP_USERNAME")
 	smtpPassword := os.Getenv("SMTP_PASSWORD")
 	smtpTLSInsecure := os.Getenv("SMTP_TLS_INSECURE") == "true"
+	from := resolveFromEmail(smtpHost)

 	// EHLO/HELO name, only relevant on the SMTP relay send path. net/smtp defaults
 	// to "localhost", which strict relays (e.g. smtp-relay.gmail.com) reject from a
@@ -245,6 +255,10 @@ func NewEmailService() *EmailService {
 // Upgrades to STARTTLS when advertised by the server.
 // Set SMTP_TLS_INSECURE=true for self-signed or private CA certificates.
 func (s *EmailService) sendSMTP(to, subject, htmlBody string) error {
+	if strings.TrimSpace(s.fromEmail) == "" {
+		return fmt.Errorf("SMTP_FROM_EMAIL or RESEND_FROM_EMAIL is required when SMTP_HOST is set")
+	}
+
 	c, err := s.openSMTPClient()
 	if err != nil {
 		return err
--- a/server/internal/service/email_test.go
+++ b/server/internal/service/email_test.go
@@ -199,6 +199,74 @@ func TestNewEmailService_EHLOName(t *testing.T) {
 	}
 }

+func TestNewEmailService_FromEmailResolution(t *testing.T) {
+	tests := []struct {
+		name          string
+		smtpHost      string
+		smtpUsername  string
+		smtpFromEmail string
+		resendFrom    string
+		want          string
+	}{
+		{
+			name:       "resend mode uses resend from",
+			resendFrom: "resend@example.com",
+			want:       "resend@example.com",
+		},
+		{
+			name:          "smtp mode prefers smtp from",
+			smtpHost:      "smtp.example.com",
+			smtpUsername:  "auth@example.com",
+			smtpFromEmail: "sender@example.com",
+			resendFrom:    "resend@example.com",
+			want:          "sender@example.com",
+		},
+		{
+			name:         "smtp mode falls back to resend from",
+			smtpHost:     "smtp.example.com",
+			smtpUsername: "auth@example.com",
+			resendFrom:   "resend@example.com",
+			want:         "resend@example.com",
+		},
+		{
+			name: "default",
+			want: "noreply@multica.ai",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Setenv("RESEND_API_KEY", "")
+			t.Setenv("SMTP_HOST", tt.smtpHost)
+			t.Setenv("SMTP_USERNAME", tt.smtpUsername)
+			t.Setenv("SMTP_FROM_EMAIL", tt.smtpFromEmail)
+			t.Setenv("RESEND_FROM_EMAIL", tt.resendFrom)
+
+			s := NewEmailService()
+			if s.fromEmail != tt.want {
+				t.Fatalf("fromEmail = %q, want %q", s.fromEmail, tt.want)
+			}
+		})
+	}
+}
+
+func TestSendSMTPRequiresConfiguredFromEmail(t *testing.T) {
+	s := &EmailService{
+		smtpHost:     "127.0.0.1",
+		smtpPort:     "1",
+		smtpUsername: "auth@example.com",
+		smtpPassword: "testpass",
+	}
+
+	err := s.sendSMTP("to@example.com", "Test Subject", "<p>Hello</p>")
+	if err == nil {
+		t.Fatal("expected missing from email error")
+	}
+	if got := err.Error(); got != "SMTP_FROM_EMAIL or RESEND_FROM_EMAIL is required when SMTP_HOST is set" {
+		t.Fatalf("error = %q, want missing from email error", got)
+	}
+}
+
 func TestBuildInvitationParams_EscapesHTMLInBody(t *testing.T) {
 	tests := []struct {
 		name          string
@@ -413,6 +481,7 @@ func TestLoginAuth_Start_AllowsLoopbackIPs(t *testing.T) {

 func TestSendSMTP_OpenClientFailureNoPanic(t *testing.T) {
 	s := &EmailService{
+		fromEmail:    "from@example.com",
 		smtpHost:     "255.255.255.255", // unroutable, will time out or fail
 		smtpPort:     "25",
 		smtpUsername: "user",
@@ -579,6 +648,7 @@ func TestSendSMTP_FallbackReconnectsAndAuthsWithLOGIN(t *testing.T) {
 	host, port, _ := net.SplitHostPort(srv.Addr)

 	s := &EmailService{
+		fromEmail:    "from@example.com",
 		smtpHost:     host,
 		smtpPort:     port,
 		smtpUsername: "testuser",
@@ -605,6 +675,7 @@ func TestSendSMTP_PlainAuthSucceedsWithoutFallback(t *testing.T) {
 	host, port, _ := net.SplitHostPort(srv.Addr)

 	s := &EmailService{
+		fromEmail:    "from@example.com",
 		smtpHost:     host,
 		smtpPort:     port,
 		smtpUsername: "testuser",
@@ -625,8 +696,9 @@ func TestSendSMTP_NoAuthWhenUsernameEmpty(t *testing.T) {
 	host, port, _ := net.SplitHostPort(srv.Addr)

 	s := &EmailService{
-		smtpHost: host,
-		smtpPort: port,
+		fromEmail: "from@example.com",
+		smtpHost:  host,
+		smtpPort:  port,
 		// smtpUsername is empty → unauthenticated relay
 	}