# Return-Path and Envelope-Sender — Quick Setup in AcelleMail

> The 5-minute setup: pick a bounce subdomain, publish the MX record, set the sending-server config, verify. This is the practical companion to [Return-path and envelope-sender explained](/kb/articles/return-path-and-envelope-sender-explained) — when you just want to do it.

- Canonical URL: https://acellesend.com/kb/articles/return-path-and-envelope-sender
- Author: Lena Hart, Email Deliverability Editor
- Category: DNS & Domain Setup — SPF, DKIM, DMARC, BIMI, domain verification, MX records, Return-Path
- Content type: tutorial · Difficulty: beginner
- Tags: Acellemail
- Published: 2026-07-04 · Last updated: 2026-08-15
- Reading time: 5 min
- Publisher: AcelleMail Knowledge Base, https://acellesend.com/kb

---

## What you're doing

You're setting up a custom envelope-sender (also called "return-path" or "MAIL FROM domain") aligned to your sending domain. Instead of AcelleMail using the vendor's default like `bounces+xxx@amazonses.com`, your envelope-sender becomes `bounce@bounce.yourdomain.com` — passing strict DMARC alignment.

This article is the 5-minute setup. For the concept + why it matters, see [Return-path and envelope-sender explained](https://acellesend.com/kb/articles/return-path-and-envelope-sender-explained).

## Step 1: Pick a subdomain

Convention: `bounce.yourdomain.com` or `mail.yourdomain.com`. Reserved for envelope-sender / return-path.

```
bounce.brand.com   (recommended; explicit)
mail.brand.com     (also common)
return.brand.com   (sometimes used)
```

## Step 2: Publish the MX record

At your DNS host:

```
Type:     MX
Name:     bounce.yourdomain.com
Value:    feedback.acellemail.com   (or your install's bounce processor)
Priority: 10
TTL:      3600
```

The exact MX target is shown in your AcelleMail sending-domain detail page. Use that value.

Wait for DNS propagation (5-60 minutes typical).

## Step 3: Configure the sending server in AcelleMail

In AcelleMail's sidebar, **Sending → Sending servers** → click your active server. The detail page surfaces Connection settings + Configuration + Identity:

![Sending server detail — Configuration section](https://acellesend.com/plugins/acelle/landing/images/help/kb/sending-servers/02-server-detail-full.png)

In the server detail's Configuration section, find the **MAIL FROM (Return-Path)** field. Enter your subdomain:

```
MAIL FROM: bounce.yourdomain.com
```

Save. From the next send onwards, AcelleMail uses this as the envelope-sender.

## Step 4: Verify

Send a test campaign to yourself. Open the received message → Gmail's "Show original" (or equivalent in your email client). Look for:

```
Return-Path: <bounce@bounce.yourdomain.com>
```

If you see your custom subdomain — done. If you see the vendor default (e.g. `bounces+xxx@amazonses.com`) — Step 3 didn't save; re-check sending server config.

Verify the DMARC alignment in AcelleMail's auth chips:
### The auth chips on the sending-server detail

Open Settings → Sending servers → click your active server. The toolbar shows the live SPF / DKIM / DMARC chip status:

![Sending server detail with auth chips](https://acellesend.com/plugins/acelle/landing/images/help/kb/spam-folder/02-sending-server-config.png)

- **Green chips on all three** = receiving servers can confirm you're authorized to send from this domain.
- **Any chip red** = receiving servers immediately downgrade reputation. Click *Verify domain* in the toolbar to walk through the DNS-fix wizard.

DMARC chip should remain Green. If it flips Red after this change, your DMARC record needs subdomain alignment too — see [DMARC enforcement migration](https://acellesend.com/kb/articles/dmarc-enforcement-migration).

## Common UI signals + fixes

| Symptom | Likely cause | UI fix |
|---|---|---|
| Bounces stop arriving in AcelleMail | MX record not propagated | `dig MX bounce.yourdomain.com` — verify target matches AcelleMail's expected value |
| MAIL FROM field grayed out | Vendor doesn't support custom MAIL FROM (some shared-pool setups) | Switch to a vendor that supports custom MAIL FROM (SES, dedicated Mailgun, etc.) |
| Custom MAIL FROM saved but messages still use vendor default | Old campaign sends using cached config | Send a fresh test; only new campaigns use the new MAIL FROM |
| DMARC chip flips Red | DMARC alignment lost | Verify SPF includes the new MAIL FROM domain |

## Aligned vs unaligned

**Aligned:**
```
From:          hello@brand.com
Envelope-Sender: bounce@bounce.brand.com
SPF check on:  bounce.brand.com (subdomain of brand.com)
DMARC: pass via aligned SPF
```

**Unaligned (default vendor):**
```
From:          hello@brand.com
Envelope-Sender: bounces+xxx@amazonses.com
SPF check on:  amazonses.com (different domain)
DMARC: pass via DKIM only (or fail if strict alignment)
```

Both work for most receivers. Aligned is preferred for B2B + strict-alignment-enforcing receivers.

<details>
<summary><strong>Advanced: multi-vendor envelope-sender management + per-tenant subdomains + automated verification</strong></summary>

**Multi-vendor envelope-sender:**

If you use multiple sending vendors, each can have its own envelope-sender subdomain:

```
Server A (SES):       bounce-ses.brand.com  → feedback-ses.acellemail.com
Server B (Mailgun):   bounce-mg.brand.com   → feedback-mg.acellemail.com
Server C (Postmark):  bounce-pm.brand.com   → feedback-pm.acellemail.com
```

Per-vendor MX. Per-vendor sending-server config. All envelope-senders align to brand.com via subdomain leeway.

**Per-tenant in SaaS context:**

For SaaS sending-on-behalf-of-customers:

```
Customer A: bounce.customerA.com → managed by your platform
Customer B: bounce.customerB.com → managed by your platform
```

Each customer adds the MX record at their DNS host. Your platform's AcelleMail config sets per-customer envelope-sender.

**Automated verification:**

```bash
#!/bin/bash
# Daily check — verify all sending-server MAIL FROM domains have correct MX
servers=$(curl -sH "Authorization: Bearer $TOKEN" \
  "https://acellemail.com/api/v1/admin/sending-servers" | jq -r '.data[].uid')

for server in $servers; do
  mail_from=$(curl -sH "Authorization: Bearer $TOKEN" \
    "https://acellemail.com/api/v1/admin/sending-servers/$server" \
    | jq -r '.mail_from_domain')

  if [ -n "$mail_from" ]; then
    mx=$(dig MX $mail_from +short | head -1)
    if [ -z "$mx" ]; then
      echo "🚨 Server $server: MAIL FROM=$mail_from has no MX record"
    fi
  fi
done
```

**Custom envelope-sender for transactional vs marketing:**

```
Transactional server: bounce-txn.brand.com  (separate reputation pool)
Marketing server:     bounce-mkt.brand.com  (separate reputation pool)
```

Bounces from each route separately. Marketing reputation problems don't pollute transactional reputation.

**Vendor-specific notes:**

- **Amazon SES**: Set "MAIL FROM domain" in SES Verified Identities. Add MX record `bounce.brand.com → feedback-smtp.us-east-1.amazonses.com` (region-dependent)
- **SendGrid**: Whitelabel feature (paid tier). Configure via SendGrid Senders → Domain Authentication
- **Mailgun**: Built-in; configure via Domain → DNS Records
- **Postmark**: Built-in; configure via Servers → Server Settings → Custom MAIL FROM

Each vendor has slightly different MX target. Refer to vendor docs OR check AcelleMail's sending-domain detail page for the right value.

</details>

## Related articles

- [Return-path and envelope-sender explained](https://acellesend.com/kb/articles/return-path-and-envelope-sender-explained)
- [How to set up SPF, DKIM, and DMARC records](https://acellesend.com/kb/articles/how-to-set-up-spf-dkim-and-dmarc-records)
- [Complete DNS setup for email sending](https://acellesend.com/kb/articles/complete-dns-setup-for-email-sending)
- [DMARC enforcement migration](https://acellesend.com/kb/articles/dmarc-enforcement-migration)

---

## Related articles

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