WordPress SMTP
Send reliable WordPress email — password resets, WooCommerce receipts, form notifications — through eusend's SMTP relay using WP Mail SMTP or FluentSMTP.
By default WordPress sends mail with PHP's mail() function, which is
unauthenticated and lands in spam or silently disappears. Pointing WordPress at
eusend's SMTP relay fixes deliverability for password resets, WooCommerce order
receipts, contact-form notifications, and every other email your site sends —
all DKIM-signed and tracked in your eusend dashboard.
This guide uses the free WP Mail SMTP plugin. FluentSMTP and Post SMTP work identically — the connection values below are the same for any of them.
Connection values
| Parameter | Type | Description |
|---|---|---|
SMTP Hostrequired | smtp.eusend.dev | The submission server. |
Encryptionrequired | SSL | Implicit TLS. Not TLS/STARTTLS. |
SMTP Portrequired | 465 | Use 2465 if your host blocks 465. |
Authenticationrequired | On | Enable "Auto TLS" and authentication. |
SMTP Usernamerequired | eusend | The literal string "eusend". |
SMTP Passwordrequired | eu_live_… | Any eusend API key. |
Setup
Install WP Mail SMTP
In WordPress admin go to Plugins → Add New, search for WP Mail SMTP by WPForms, install it, and activate. A WP Mail SMTP item appears in the sidebar.
Choose the "Other SMTP" mailer
Open WP Mail SMTP → Settings. Under Mailer, pick Other SMTP.
Set the From address
Set From Email to an address on a domain you have
verified in eusend — for example [email protected].
Set From Name to your site name, and tick Force From Email so plugins
can't override it with an unverified address.
Enter the SMTP connection
Fill in the connection fields:
SMTP Host: smtp.eusend.dev
Encryption: SSL
SMTP Port: 465
Authentication: On
SMTP Username: eusend
SMTP Password: <an eusend API key, eu_live_…>Save.
Send a test email
Open the Email Test tab, enter your own address, and send. A delivered test confirms the whole path. The message also shows up in your eusend dashboard.
Set From Email to a verified domain and enable Force From Email. If
WooCommerce or a form plugin sends from an unverified domain, eusend rejects it
with a 550.
WooCommerce
No extra configuration is needed. Once WP Mail SMTP routes mail through eusend, WooCommerce order confirmations, invoices, and shipping notifications go through the same relay automatically — just make sure the WooCommerce "From" address (WooCommerce → Settings → Emails) is also on your verified domain.
Troubleshooting
| Symptom | Cause |
|---|---|
SMTP Error: Could not authenticate (535) | Username isn't the literal eusend, or the API key is wrong. The key goes in the password field. |
Mail rejected with 550 | The From address is on an unverified domain, or the recipient is suppressed. |
| Test times out on port 465 | Your host blocks 465 — switch the port to 2465. |
See the SMTP overview for limits and the full status-code table.
SMTP
Send through eusend over SMTP instead of the HTTP API — a drop-in transport for anything that already speaks SMTP, from WordPress and Supabase to Django, Laravel, and Rails.
Supabase SMTP
Send Supabase Auth emails — confirmations, magic links, password resets — through eusend by configuring custom SMTP in your Supabase project.