Send email over SMTP¶
Email from your website's contact form, an online shop, a CRM or a multifunction printer (scan to email) can go out through DUO. The device sends to DUO's SMTP server, which signs the messages with your domain and records deliveries, opens and bounces.
Before you start¶
- The sender's domain must be active in DUO. See Set up your sending domain.
- SMTP sending must be enabled on your account. Sooma enables it during onboarding; if you're not sure, ask ajuda@sooma.pt.
1. Choose the contact list¶
Every recipient of an email sent over SMTP becomes a contact in a DUO list. Create a list just for these messages, for example "Website messages", under Contact lists → New.
Set Double optin required to No. With confirmation on, new recipients wait for confirmation and their messages are refused.
2. Create the transactional send¶
- Under Transactional Sends, click New Transactional Send.
-
Fill in:
Field Value Name A name that identifies the source, for example "Website and printers" Contact List The list from step 1 Used for SMTP submission Yes Send delivery status notifications No to discard bounce notices; Yes to forward them to the sender -
Click Create.
The send's page now shows the connection details: server, port and user.
Warning
Keep only one transactional send with Used for SMTP submission: Yes per account. If there are several, DUO uses just one of them.
3. Configure the device¶
| Setting | Value |
|---|---|
| SMTP server | smtp-01.duo.pt |
| Port | 587 |
| Encryption | STARTTLS |
| Authentication | Yes (PLAIN or LOGIN) |
| Username | Your DUO account username, shown at the top right of the application |
| Password | Your DUO account password |
| Sender (From) | An address on the active domain, for example no-reply@example.com |
If you change your DUO account password, update it on every configured device.
Note
Some older printers don't support STARTTLS on port 587. If yours doesn't, contact us.
4. Test¶
Send a test email to one of your own addresses. On the transactional send's page, View events shows the delivery, the open and any clicks.
When a message is refused¶
The device hands the message to the server without an error, but DUO may refuse it afterwards. The sender then receives a bounce from MAILER-DAEMON@duo.pt with the subject Undelivered Mail Returned to Sender and the reason in the text:
| Reason in the bounce | What it means | What to do |
|---|---|---|
Domain example.com in header-from not authorized |
The sender's domain is not in your account | Add and activate the domain, or change the sender to an active domain |
User … has no transactional send |
No transactional send has SMTP enabled | Do step 2 |
User … has no SMTP Server |
SMTP sending is not enabled on the account | Contact ajuda@sooma.pt |
Contact has unsubscribed |
The recipient unsubscribed from the list | The contact must subscribe again |
Contact is bouncing |
Earlier messages to this address bounced | Check the address; once fixed, contact us to reactivate it |
Contact opt-in is pending |
The list requires subscription confirmation | Turn confirmation off on the list (step 1) |
To set this up through the API, see the smtp_submission parameter in Transactional.