> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://revoq.crisp.help/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# Set up a custom sender domain for confirmation emails

**On the Professional plan, you can send confirmation emails from your own custom domain – instead of the default `confirmation@consumer-withdrawal.eu`. This looks more consistent to your customers and reduces the chance of spam classification.**

You have two options: a classic SMTP server or a Microsoft 365 integration via OAuth2. Both work – pick the one that fits your existing email infrastructure.

# When this makes sense

* You want your customers to see your own domain as the sender of the confirmation email
* Your email provider gives you better tracking and logging for sent emails
* You already use the same domain for email marketing and want to consolidate sender reputation

# Requirements

* You're on the **Professional plan**
* You have access to an **SMTP server** with sending permissions
* OR: You have a **Microsoft 365 mailbox** that can send emails
* Your domain has configured **SPF and ideally DKIM records** – otherwise emails often land in spam

# Option A: Connect an SMTP server

1. In your Revoq admin, go to **Settings → Email Settings**.
2. In the **Custom sender domain** section, select **SMTP**.
3. Enter the connection details:
* **Host** (e.g. `smtp.yourprovider.com`)
* **Port** (typically 587 with STARTTLS or 465 with SSL)
* **Encryption** (TLS recommended)
* **Username**
* **Password** – many providers require an **app-specific password** rather than your regular login
* **Sender email address** (the address your customers see, e.g. `withdrawals@yourshop.com`)
4. Save.

![](https://storage.crisp.chat/users/helpdesk/website/-/9/d/0/a/9d0aebb43b89f800/bildschirmfoto-2026-06-10-um-1_1ys9tjm.png)
![](https://storage.crisp.chat/users/helpdesk/website/-/9/d/0/a/9d0aebb43b89f800/bildschirmfoto-2026-06-10-um-1_tirg7x.png)


| Tip: Google Workspace, Yahoo, and many other providers no longer allow direct password logins. Generate an app password in your mail account's security settings and use that instead of your regular password.

# Helpful links for common providers

If you're not sure where to find your provider's SMTP details or how to generate an app password, here are the official guides for the most common providers:

* **Gmail / Google Workspace:** [Create an app password](https://support.google.com/accounts/answer/185833) – app passwords are managed at [myaccount.google.com/apppasswords](https://myaccount.google.com/apppasswords). 2-step verification must be enabled.
* **Strato:** [Use your email address with external clients](https://www.strato.de/faq/mail/externes-e-mail-programm-mit-strato-e-mail-adresse-nutzen/) – contains SMTP server, ports, and authentication details (German).
* **IONOS:** [Server information for IMAP, POP3, and SMTP](https://www.ionos.de/hilfe/e-mail/allgemeine-themen/serverinformationen-fuer-imap-pop3-und-smtp/) – all server addresses and ports at a glance (German).

|| Note: IONOS introduced an additional rule in 2024 – the sender address must match the domain of the configured mailbox. Example: If you want to send from `withdrawals@yourshop.com`, the SMTP mailbox must also be on `yourshop.com`.

# Option B: Connect Microsoft 365 (OAuth2)

If your company uses Microsoft 365, OAuth2 is the easier path – no password management in Revoq, no app passwords needed.

1. In your Revoq admin, go to **Settings → Email Settings**.
2. In the **Custom sender domain** section, select **Microsoft 365**.
3. Click **Sign in with Microsoft**.
4. In the Microsoft login, sign in with the mailbox you want to send emails from.
5. Confirm the permission for Revoq.
6. You'll be redirected back to the app and see the connection as active.

![](https://storage.crisp.chat/users/helpdesk/website/-/9/d/0/a/9d0aebb43b89f800/bildschirmfoto-2026-06-10-um-1_ely5uq.png)


|| Note: In some Microsoft 365 tenants, external apps need to be centrally approved by an administrator. If your login fails with an error message, contact your IT admin. Microsoft has detailed documentation on the topic: [Authenticate an IMAP, POP, or SMTP connection using OAuth](https://learn.microsoft.com/en-us/exchange/client-developer/legacy-protocols/how-to-authenticate-an-imap-pop-smtp-application-by-using-oauth) – useful for the person granting app permissions.

# Send and verify a test email

Before real customers use the new configuration, send yourself a test email:

1. In the email settings, you'll find a **Send test** button.
2. Enter a recipient address in merchant notifications (ideally your own).
3. Click **Send test** and verify the email arrives – with the correct sender, clean layout, and no spam marking.

||| Important: Always send a test email before marking the configuration as active. A broken SMTP configuration can prevent sending the confirmation email from your domain.

# What happens if sending fails?

If your SMTP server or Microsoft 365 can't send the email for any reason (server outage, expired OAuth token, etc.), Revoq automatically falls back to standard delivery. Your customers still receive the confirmation – just from the default sender `confirmation@consumer-withdrawal.eu`.

You'll be notified in the dashboard so you can restore the connection.

# Troubleshooting

**Authentication fails:**
For SMTP, double-check username and password. Many providers require app passwords instead of regular logins.

**Test email doesn't arrive:**
Check spam folder and your domain's SPF/DKIM records. Tools like [MXToolbox](https://mxtoolbox.com/) help with DNS diagnostics.

**Microsoft 365 connects but email is rejected:**
Check mailbox permissions in your Microsoft Admin Center, and verify that "Send As" is allowed for your sender address.

**Token expires (Microsoft 365):**
OAuth tokens are renewed automatically. If renewal fails, simply sign in again via the Microsoft login.

# Related

* [Set up email notifications for new withdrawals](https://revoq.crisp.help/en/article/set-up-email-notifications-for-new-withdrawals-eq6naw/)
* [FAQ](https://revoq.crisp.help/en/article/faq-x9z1jn/)
* [Go-Live Checklist](https://revoq.crisp.help/en/article/go-live-checklist-are-you-ready-for-june-19-2026-1ppy570/)