knadh · knadh · Aug 18, 2025 · Jul 8, 2026
diff --git a/cmd/campaigns.go b/cmd/campaigns.go
@@ -688,7 +688,8 @@ func (a *App) validateCampaignFields(c campReq) (campReq, error) {
 		c.ContentType != models.CampaignContentTypeHTML &&
 		c.ContentType != models.CampaignContentTypePlain &&
 		c.ContentType != models.CampaignContentTypeVisual &&
-		c.ContentType != models.CampaignContentTypeMarkdown {
+		c.ContentType != models.CampaignContentTypeMarkdown &&
+		c.ContentType != models.CampaignContentTypeMJML {
 		c.ContentType = models.CampaignContentTypeRichtext
 	}
 
@@ -716,9 +717,24 @@ func (a *App) validateCampaignFields(c campReq) (campReq, error) {
 		}
 	}
 
-	camp := models.Campaign{Body: c.Body, TemplateBody: tplTag}
-	if err := c.CompileTemplate(a.manager.TemplateFuncs(&camp)); err != nil {
-		return c, errors.New(a.i18n.Ts("campaigns.fieldInvalidBody", "error", err.Error()))
+	// Empty MJML drafts are valid while creating/editing, but gomjml rejects
+	// an empty document with EOF. Validate only when there's something to compile.
+	shouldCompile := c.ContentType != models.CampaignContentTypeMJML || strings.TrimSpace(c.Body) != ""
+	if shouldCompile {
+		templateBody := tplTag
+
+		if c.ContentType == models.CampaignContentTypeMJML && c.TemplateID.Valid && c.TemplateID.Int > 0 {
+			tpl, err := a.core.GetTemplate(c.TemplateID.Int, false)
+			if err != nil {
+				return c, err
+			}
+			templateBody = tpl.Body
+		}
+
+		camp := models.Campaign{Body: c.Body, ContentType: c.ContentType, TemplateBody: templateBody}
+		if err := camp.CompileTemplate(a.manager.TemplateFuncs(&camp)); err != nil {
+			return c, errors.New(a.i18n.Ts("campaigns.fieldInvalidBody", "error", err.Error()))
+		}
 	}
 
 	if len(c.Headers) == 0 {

diff --git a/cmd/install.go b/cmd/install.go
@@ -237,6 +237,15 @@ func installTemplates(q *models.Queries) (int, int) {
 		lo.Fatalf("error creating default campaign template: %v", err)
 	}
 
+	// Insert MJML template.
+	tpl, err := fs.Get("/static/email-templates/sample-mjml.tpl")
+	if err != nil {
+		lo.Fatalf("error reading sample mjml template: %v", err)
+	}
+	if _, err := q.CreateTemplate.Exec("Sample MJML template", models.TemplateTypeCampaign, "", tpl.ReadBytes(), nil); err != nil {
+		lo.Fatalf("error creating mjml campaign template: %v", err)
+	}
+
 	return campTplID, archiveTplID
 }
 

diff --git a/frontend/src/components/CodeEditor.vue b/frontend/src/components/CodeEditor.vue
@@ -50,6 +50,9 @@ export default {
       case 'html':
         langs = [html()];
         break;
+      case 'mjml':
+        langs = [html()];
+        break;
       case 'css':
         langs = [css()];
         break;

diff --git a/frontend/src/components/Editor.vue b/frontend/src/components/Editor.vue
@@ -67,6 +67,9 @@
     <!-- raw html editor //-->
     <code-editor lang="html" v-if="self.contentType === 'html'" v-model="self.body" key="editor-html" />
 
+    <!-- mjml editor //-->
+    <code-editor lang="mjml" v-if="self.contentType === 'mjml'" v-model="self.body" key="editor-mjml" />
+
     <!-- markdown editor //-->
     <code-editor lang="markdown" v-if="self.contentType === 'markdown'" v-model="self.body" key="editor-markdown" />
 
@@ -162,7 +165,7 @@ export default {
 
       // If `from` is HTML content, strip out `<body>..` etc. and keep the beautified HTML.
       let isHTML = false;
-      if (from === 'richtext' || from === 'html' || from === 'visual') {
+      if (from === 'richtext' || from === 'html' || from === 'visual' || from === 'mjml') {
         const d = document.createElement('div');
         d.innerHTML = body;
         body = this.beautifyHTML(d.innerHTML.trim());
@@ -198,7 +201,7 @@ export default {
         }
 
         // Markdown to HTML requires a backend call.
-      } else if (from === 'markdown' && (to === 'richtext' || to === 'html')) {
+      } else if (from === 'markdown' && (to === 'richtext' || to === 'html' || to === 'mjml')) {
         skip = true;
         this.$api.convertCampaignContent({
           id: 1, body, from, to,
@@ -212,8 +215,21 @@ export default {
         });
 
         // Plain to an HTML type, change plain line breaks to HTML breaks.
-      } else if (from === 'plain' && (to === 'richtext' || to === 'html')) {
+      } else if (from === 'plain' && (to === 'richtext' || to === 'html' || to === 'mjml')) {
         body = body.replace(/\n/ig, '<br>\n');
+      } else if (from === 'mjml' && (to === 'richtext' || to === 'html')) {
+        // MJML to HTML requires a backend call.
+        skip = true;
+        this.$api.convertCampaignContent({
+          id: 1, body, from, to,
+        }).then((data) => {
+          this.$nextTick(() => {
+            // Both type + body should be updated in one cycle to avoid firing
+            // multiple events.
+            this.self.contentType = to;
+            this.self.body = this.beautifyHTML(data.trim());
+          });
+        });
       } else if (to === 'visual') {
         bodySource = JSON.stringify(markdownToVisualBlock(body));
       }

diff --git a/frontend/src/views/Campaign.vue b/frontend/src/views/Campaign.vue
@@ -349,6 +349,7 @@ export default Vue.extend({
         markdown: this.$t('campaigns.markdown'),
         plain: this.$t('campaigns.plainText'),
         visual: this.$t('campaigns.visual'),
+        mjml: 'MJML',
       }),
 
       isNew: false,

diff --git a/go.mod b/go.mod
@@ -30,6 +30,7 @@ require (
 	github.com/lib/pq v1.10.9
 	github.com/paulbellamy/ratecounter v0.2.0
 	github.com/pquerna/otp v1.5.0
+	github.com/preslavrachev/gomjml v0.12.0
 	github.com/rhnvrm/simples3 v0.9.1
 	github.com/spf13/pflag v1.0.6
 	github.com/yuin/goldmark v1.7.12

diff --git a/go.sum b/go.sum
@@ -8,8 +8,12 @@ github.com/Masterminds/semver/v3 v3.4.0 h1:Zog+i5UMtVoCU8oKka5P7i9q9HgrJeGzI9SA1
 github.com/Masterminds/semver/v3 v3.4.0/go.mod h1:4V+yj/TJE1HU9XfppCwVMZq3I84lprf4nC11bSS5beM=
 github.com/Masterminds/sprig/v3 v3.3.0 h1:mQh0Yrg1XPo6vjYXgtf5OtijNAKJRNcTdOOGZe3tPhs=
 github.com/Masterminds/sprig/v3 v3.3.0/go.mod h1:Zy1iXRYNqNLUolqCpL4uhk6SHUMAOSCzdgBfDb35Lz0=
+github.com/PuerkitoBio/goquery v1.10.3 h1:pFYcNSqHxBD06Fpj/KsbStFRsgRATgnf3LeXiUkhzPo=
+github.com/PuerkitoBio/goquery v1.10.3/go.mod h1:tMUX0zDMHXYlAQk6p35XxQMqMweEKB7iK7iLNd4RH4Y=
 github.com/altcha-org/altcha-lib-go v1.0.0 h1:7oPti0aUS+YCep8nwt5b9g4jYfCU55ZruWESL8G9K5M=
 github.com/altcha-org/altcha-lib-go v1.0.0/go.mod h1:I8ESLVWR9C58uvGufB/AJDPhaSU4+4Oh3DLpVtgwDAk=
+github.com/andybalholm/cascadia v1.3.3 h1:AG2YHrzJIm4BZ19iwJ/DAua6Btl3IwJX+VI4kktS1LM=
+github.com/andybalholm/cascadia v1.3.3/go.mod h1:xNd9bqTn98Ln4DwST8/nG+H0yuB8Hmgu1YHNnWw0GeA=
 github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc h1:biVzkmvwrH8WK8raXaxBx6fRVTlJILwEwQGL1I/ByEI=
 github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/coreos/go-oidc/v3 v3.14.1 h1:9ePWwfdwC4QKRlCXsJGou56adA/owXczOzwKdOumLqk=
@@ -108,6 +112,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pquerna/otp v1.5.0 h1:NMMR+WrmaqXU4EzdGJEE1aUUI0AMRzsp96fFFWNPwxs=
 github.com/pquerna/otp v1.5.0/go.mod h1:dkJfzwRKNiegxyNb54X/3fLwhCynbMspSyWKnvi1AEg=
+github.com/preslavrachev/gomjml v0.12.0 h1:woWveeBIQ8OsU1PeCxZO5Y3KL6xJqyV6LdtPlFtn408=
+github.com/preslavrachev/gomjml v0.12.0/go.mod h1:10tpMJhl+46mqf+5wG18fOXaWNB+OOllCpksDRJlJTU=
 github.com/rhnvrm/simples3 v0.9.1 h1:pYfEe2wTjx8B2zFzUdy4kZn3I3Otd9ZvzIhHkFR85kE=
 github.com/rhnvrm/simples3 v0.9.1/go.mod h1:Y+3vYm2V7Y4VijFoJHHTrja6OgPrJ2cBti8dPGkC3sA=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=

diff --git a/internal/migrations/v6.2.0.go b/internal/migrations/v6.2.0.go
@@ -8,6 +8,7 @@ import (
 	"github.com/knadh/stuffbin"
 )
 
+// V6_2_0 performs the DB migrations for v6.2.0.
 func V6_2_0(db *sqlx.DB, fs stuffbin.FileSystem, ko *koanf.Koanf, lo *log.Logger) error {
 	// Add `msg_retry_delay` to each SMTP server entry in the `smtp` settings JSON array.
 	// Idempotent: only updates rows where at least one entry is missing the key.
@@ -62,5 +63,23 @@ func V6_2_0(db *sqlx.DB, fs stuffbin.FileSystem, ko *koanf.Koanf, lo *log.Logger
 		return err
 	}
 
+	// Add MJML to content_type enum if not exists.
+	if _, err := db.Exec(`ALTER TYPE content_type ADD VALUE IF NOT EXISTS 'mjml';`); err != nil {
+		return err
+	}
+
+	// Insert sample MJML template.
+	tpl, err := fs.Get("/static/email-templates/sample-mjml.tpl")
+	if err != nil {
+		return err
+	}
+	if _, err := db.Exec(`
+		INSERT INTO templates (name, type, subject, body)
+		SELECT $1, $2::template_type, $3, $4
+		WHERE NOT EXISTS (SELECT 1 FROM templates WHERE name = $1 AND type = $2::template_type);`,
+		"Sample MJML template", "campaign", "", tpl.ReadBytes()); err != nil {
+		return err
+	}
+
 	return nil
 }
diff --git a/models/campaigns.go b/models/campaigns.go
@@ -12,6 +12,7 @@ import (
 	"github.com/jmoiron/sqlx"
 	"github.com/jmoiron/sqlx/types"
 	"github.com/lib/pq"
+	"github.com/preslavrachev/gomjml/mjml"
 	null "gopkg.in/volatiletech/null.v6"
 )
 
@@ -29,6 +30,7 @@ const (
 	CampaignContentTypeMarkdown = "markdown"
 	CampaignContentTypePlain    = "plain"
 	CampaignContentTypeVisual   = "visual"
+	CampaignContentTypeMJML     = "mjml"
 )
 
 // Campaigns represents a slice of Campaigns.
@@ -156,28 +158,50 @@ func (c *Campaign) CompileTemplate(f template.FuncMap) error {
 
 	// Compile the base template.
 	body := c.TemplateBody
+	hasBaseTpl := body != ""
 
-	if body == "" || c.ContentType == CampaignContentTypeVisual {
+	if !hasBaseTpl || c.ContentType == CampaignContentTypeVisual {
 		body = `{{ template "content" . }}`
 	}
 
 	for _, r := range regTplFuncs {
 		body = r.regExp.ReplaceAllString(body, r.replace)
 	}
 
+	// For an MJML campaign, the entire body is one MJML document. Substitute
+	// the campaign body for the `{{ template "content" . }}` placeholder in
+	// the base, then run mjml.Render once.
+	if c.ContentType == CampaignContentTypeMJML {
+		campBody := c.Body
+		for _, r := range regTplFuncs {
+			campBody = r.regExp.ReplaceAllString(campBody, r.replace)
+		}
+		b := regexpTplTag.ReplaceAllLiteralString(body, campBody)
+		htmlBody, err := mjml.Render(b)
+		if err != nil {
+			return fmt.Errorf("error compiling MJML: %v", err)
+		}
+		body = htmlBody
+	}
+
 	baseTPL, err := template.New(BaseTpl).Funcs(f).Parse(body)
 	if err != nil {
 		return fmt.Errorf("error compiling base template: %v", err)
 	}
 
-	// If the format is markdown, convert Markdown to HTML.
-	if c.ContentType == CampaignContentTypeMarkdown {
+	// Pick the body to assign to the `content` sub-template.
+	switch c.ContentType {
+	case CampaignContentTypeMJML:
+		body = ""
+
+	case CampaignContentTypeMarkdown:
 		var b bytes.Buffer
 		if err := markdown.Convert([]byte(c.Body), &b); err != nil {
 			return err
 		}
 		body = b.String()
-	} else {
+
+	default:
 		body = c.Body
 	}
 
@@ -258,12 +282,19 @@ func (c *Campaign) ConvertContent(from, to string) (string, error) {
 	// If the format is markdown, convert Markdown to HTML.
 	var out string
 	if from == CampaignContentTypeMarkdown &&
-		(to == CampaignContentTypeHTML || to == CampaignContentTypeRichtext) {
+		(to == CampaignContentTypeHTML || to == CampaignContentTypeRichtext || to == CampaignContentTypeMJML) {
 		var b bytes.Buffer
 		if err := markdown.Convert([]byte(c.Body), &b); err != nil {
 			return out, err
 		}
 		out = b.String()
+	} else if from == CampaignContentTypeMJML &&
+		(to == CampaignContentTypeHTML || to == CampaignContentTypeRichtext) {
+		htmlBody, err := mjml.Render(c.Body)
+		if err != nil {
+			return out, fmt.Errorf("error converting MJML: %v", err)
+		}
+		out = htmlBody
 	} else {
 		return out, errors.New("unknown formats to convert")
 	}

diff --git a/models/common.go b/models/common.go
@@ -40,6 +40,10 @@ type regTplFunc struct {
 	replace string
 }
 
+// regexpTplTag matches a `{{ template "content" . }}` directive with any
+// amount of internal whitespace.
+var regexpTplTag = regexp.MustCompile(`{{\s*template\s+"content"\s+\.\s*}}`)
+
 var regTplFuncs = []regTplFunc{
 	// Regular expression for matching {{ TrackLink "http://link.com" }} in the template
 	// and substituting it with {{ TrackLink "http://link.com" . }} (the dot context)

diff --git a/schema.sql b/schema.sql
@@ -5,7 +5,7 @@ DROP TYPE IF EXISTS subscriber_status CASCADE; CREATE TYPE subscriber_status AS
 DROP TYPE IF EXISTS subscription_status CASCADE; CREATE TYPE subscription_status AS ENUM ('unconfirmed', 'confirmed', 'unsubscribed');
 DROP TYPE IF EXISTS campaign_status CASCADE; CREATE TYPE campaign_status AS ENUM ('draft', 'running', 'scheduled', 'paused', 'cancelled', 'finished');
 DROP TYPE IF EXISTS campaign_type CASCADE; CREATE TYPE campaign_type AS ENUM ('regular', 'optin');
-DROP TYPE IF EXISTS content_type CASCADE; CREATE TYPE content_type AS ENUM ('richtext', 'html', 'plain', 'markdown', 'visual');
+DROP TYPE IF EXISTS content_type CASCADE; CREATE TYPE content_type AS ENUM ('richtext', 'html', 'plain', 'markdown', 'visual', 'mjml');
 DROP TYPE IF EXISTS bounce_type CASCADE; CREATE TYPE bounce_type AS ENUM ('soft', 'hard', 'complaint');
 DROP TYPE IF EXISTS template_type CASCADE; CREATE TYPE template_type AS ENUM ('campaign', 'campaign_visual', 'tx');
 DROP TYPE IF EXISTS user_type CASCADE; CREATE TYPE user_type AS ENUM ('user', 'api');

diff --git a/static/email-templates/sample-mjml.tpl b/static/email-templates/sample-mjml.tpl
@@ -0,0 +1,41 @@
+<mjml>
+  <mj-head>
+    <mj-title>{{ .Campaign.Subject }}</mj-title>
+    <mj-preview>{{ .Campaign.Subject }}</mj-preview>
+  </mj-head>
+  <mj-body background-color="#F0F1F3">
+    <!-- Spacer -->
+    <mj-section padding="30px 0">
+      <mj-column>
+        <mj-text>&nbsp;</mj-text>
+      </mj-column>
+    </mj-section>
+
+    <!-- Main Content Wrapper -->
+    <mj-section background-color="#fff" border-radius="5px" padding="30px">
+      <mj-column>
+        {{ template "content" . }}
+      </mj-column>
+    </mj-section>
+
+    <!-- Footer -->
+    <mj-section padding="20px 0">
+      <mj-column>
+        <mj-text align="center" font-size="12px" color="#888">
+          <a href="{{ UnsubscribeURL }}" style="color: #888; margin-right: 5px;">{{ L.T "email.unsub" }}</a>
+          &nbsp;&nbsp;
+          <a href="{{ MessageURL }}" style="color: #888; margin-right: 5px;">{{ L.T "email.viewInBrowser" }}</a>
+        </mj-text>
+      </mj-column>
+    </mj-section>
+
+    <!-- Bottom Spacer with Tracking -->
+    <mj-section padding="30px 0">
+      <mj-column>
+        <mj-raw>
+          &nbsp;{{ TrackView }}
+        </mj-raw>
+      </mj-column>
+    </mj-section>
+  </mj-body>
+</mjml>