Email setup
Email settings live at Admin → Email. Configuration takes effect immediately without a server restart — changes are read at send time.
Without email configured, Nexus still runs normally. Email-dependent features (registration verification, password reset, magic links, notifications, and digest emails) simply won’t deliver.
What Nexus sends
Section titled “What Nexus sends”| Trigger | |
|---|---|
| Email verification | On registration when “Require email verification” is enabled |
| Magic link | When a user requests passwordless sign-in |
| Notification emails | Replies, reactions, mentions, DMs, and badge awards |
| Moderation report | When a content report is submitted — sent to moderators |
| Digest email | Scheduled weekly or monthly community summary |
All emails are sent as both HTML and plain text. HTML emails use the forum’s accent color and logo.
Providers
Section titled “Providers”Nexus supports four delivery providers. Select one from the Provider dropdown at Admin → Email.
Works with any SMTP relay — your own mail server, Gmail, Fastmail, SendGrid SMTP, Mailchimp Transactional, and so on.
| Field | Description |
|---|---|
| From address | The From: address on all outgoing email, e.g. hello@yourdomain.com |
| From name | The display name shown in email clients, e.g. My Forum. Defaults to Nexus |
| SMTP host | Your relay’s hostname, e.g. smtp.sendgrid.net |
| Port | Default: 587 |
| Encryption | STARTTLS (587), SSL/TLS (465), or None (25) |
| SMTP username | Your relay’s username or email address |
| SMTP password | Your relay’s password or API key |
If no SMTP host is configured, Nexus falls back to a local in-memory adapter that accepts email silently without delivering it. This is the default dev behaviour and should not be used in production.
Postmark
Section titled “Postmark”| Field | Description |
|---|---|
| From address | Must be a verified sender address or domain in your Postmark account |
| From name | Display name for outgoing email |
| Server API token | Found in your Postmark account under API Tokens. Format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx |
Resend
Section titled “Resend”| Field | Description |
|---|---|
| From address | Must be a verified domain in your Resend account |
| From name | Display name for outgoing email |
| API key | Found in your Resend dashboard. Format: re_xxxxxxxxxxxx |
Mailgun
Section titled “Mailgun”| Field | Description |
|---|---|
| From address | Must match a verified sending domain in Mailgun |
| From name | Display name for outgoing email |
| API key | Your Mailgun API key. Format: key-xxxxxxxxxxxx |
| Domain | Your Mailgun sending domain, e.g. mg.yourdomain.com |
Testing delivery
Section titled “Testing delivery”After entering your credentials, use the Send test email button at the bottom of Admin → Email. This sends a test email to your own account’s email address. Check your inbox — if it doesn’t arrive within a minute, check your spam folder and verify your credentials.
Email and your logo
Section titled “Email and your logo”Nexus emails include your forum logo at the top if a logo URL is set under Admin → Forum info → Site logo. If no logo is set, the forum name is displayed as text instead.
Logos stored locally (uploaded via the admin panel) are referenced with an absolute URL constructed from your PHX_HOST setting in /opt/nexus/.env. If your forum’s domain changes, re-upload the logo so the URL is updated.
DNS records for deliverability
Section titled “DNS records for deliverability”Regardless of which provider you use, email deliverability requires DNS records on your sending domain. Your provider’s documentation will give you the exact values to add, but in general you’ll need:
- SPF — authorises your provider to send on behalf of your domain
- DKIM — a cryptographic signature verifying the email’s origin
- DMARC — a policy record instructing receiving servers how to handle failures
Without these records, email from your forum will frequently land in spam or be rejected outright. All four providers above have detailed setup guides for configuring these records.