SMTP / Email Delivery

Simple PHP IPAM sends email for utilization alerts. By default it uses PHP's native mail() function, which relies on your server's local MTA (Postfix, Sendmail, etc.). Starting in v3.1.0 you can configure direct SMTP delivery via PHPMailer — useful when your server has no local MTA or when you want reliable delivery via a cloud provider.

Configuration

Settings live in Admin → Settings → SMTP / Email Delivery.

Setting	Default	Description
`smtp.enabled`	`false`	Enable SMTP. When off, native `mail()` is used.
`smtp.host`	—	SMTP server hostname (e.g. `smtp.gmail.com`)
`smtp.port`	`587`	TCP port — 587 (STARTTLS), 465 (SSL), 25 (plain)
`smtp.encryption`	`starttls`	`starttls`, `ssl`, or `none`
`smtp.auth_user`	—	SMTP username. Leave blank for anonymous relay.
`smtp.auth_pass`	—	SMTP password. Stored encrypted; never logged.
`smtp.from_address`	—	Envelope From address (e.g. `ipam@example.com`)
`smtp.from_name`	—	From display name (e.g. `IPAM Alerts`)
`smtp.verify_peer`	`true`	Verify TLS certificate. Disable only for dev/test.
`smtp.timeout_seconds`	`10`	Connection timeout in seconds.

After saving, use the Send test email button on the same settings card to verify delivery. The test email is sent to the logged-in admin's email address (set in Users).

Provider examples

Gmail (App Password)

Enable 2-Factor Authentication on your Google account.
Create an App Password: Google Account → Security → App Passwords.
Settings:
- Host: smtp.gmail.com
- Port: 587
- Encryption: STARTTLS
- Username: your Gmail address
- Password: the 16-character App Password

Office 365 / Microsoft 365

Host: smtp.office365.com
Port: 587
Encryption: STARTTLS
Username: your M365 address
Password: your M365 password (or an App Password if MFA is enforced)

AWS SES (SMTP interface)

Verify a sending domain or address in the SES console.
Create SMTP credentials: SES → SMTP Settings → Create SMTP Credentials.
Settings:
- Host: email-smtp.<region>.amazonaws.com (e.g. email-smtp.us-east-1.amazonaws.com)
- Port: 587
- Encryption: STARTTLS
- Username / Password: from the SMTP credentials you created

Mailgun (SMTP API)

Host: smtp.mailgun.org
Port: 587
Encryption: STARTTLS
Username: postmaster@<your-domain>
Password: your Mailgun SMTP password (from Sending → Domain Settings → SMTP Credentials)

Postfix (local relay)

If your server runs Postfix and you want IPAM to relay through it without authentication:

smtp.enabled: true
Host: 127.0.0.1
Port: 25
Encryption: none
Auth username / password: leave blank
smtp.verify_peer: leave true (no TLS negotiated on plain port 25)

Alternatively, leave smtp.enabled as false and let PHP's mail() hand off to Postfix directly.

Troubleshooting

"Send failed via smtp" — Check the audit log (Admin → Audit) for the mail.send_failed entry; the error field contains the PHPMailer exception message. Common causes:

Wrong host/port
TLS certificate mismatch (try disabling smtp.verify_peer temporarily)
Authentication failure (wrong username/password, app-password not generated)

Test email never arrives — Check spam/junk. SPF, DKIM, and DMARC records for your sending domain improve deliverability.

Using smtp.enabled = false but mail() doesn't work — Check that your server has a local MTA configured. On Debian/Ubuntu: sudo apt install postfix. On Alpine (Docker): install and start opensmtpd or use SMTP mode instead.