Email

Overview

The Email provider uses email to send "magic links" that can be used to sign in, you will likely have seen these if you have used services like Slack before.

Adding support for signing in via email in addition to one or more OAuth services provides a way for users to sign in if they lose access to their OAuth account (e.g. if it is locked or deleted).

The Email provider can be used in conjunction with (or instead of) one or more OAuth providers.

How it works

On initial sign in, a Verification Token is sent to the email address provided. By default this token is valid for 24 hours. If the Verification Token is used with that time (i.e. by clicking on the link in the email) an account is created for the user and they are signed in.

If someone provides the email address of an existing account when signing in, an email is sent and they are signed into the account associated with that email address when they follow the link in the email.

tip

The Email Provider can be used with both JSON Web Tokens and database sessions, but you must configure a database to use it. It is not possible to enable email sign in without using a database.

Configuration

  1. You will need an SMTP account; ideally for one of the services known to work with nodemailer.

  2. There are two ways to configure the SMTP server connection.

    You can either use a connection string or a nodemailer configuration object.

    2.1 Using a connection string

    Create an .env file to the root of your project and add the connection string and email address.

    .env
    EMAIL_SERVER=smtp://username:password@smtp.example.com:587
    EMAIL_FROM=noreply@example.com

    Now you can add the email provider like this:

    pages/api/auth/[...nextauth].js
    providers: [
    Providers.Email({
    server: process.env.EMAIL_SERVER,
    from: process.env.EMAIL_FROM
    }),
    ],

    2.2 Using a configuration object

    In your .env file in the root of your project simply add the configuration object options individually:

    .env
    EMAIL_SERVER_USER=username
    EMAIL_SERVER_PASSWORD=password
    EMAIL_SERVER_HOST=smtp.example.com
    EMAIL_SERVER_PORT=587
    EMAIL_FROM=noreply@example.com

    Now you can add the provider settings to the NextAuth options object in the Email Provider.

    pages/api/auth/[...nextauth].js
    providers: [
    Providers.Email({
    server: {
    host: process.env.EMAIL_SERVER_HOST,
    port: process.env.EMAIL_SERVER_PORT,
    auth: {
    user: process.env.EMAIL_SERVER_USER,
    pass: process.env.EMAIL_SERVER_PASSWORD
    }
    },
    from: process.env.EMAIL_FROM
    }),
    ],
  3. You can now sign in with an email address at /api/auth/signin.

    An account will not be created for the user until the first time they verify their email address. If an email address already associated with an account, the user will be signed in to that account when they use the link in the email.

Customising emails

You can fully customise the sign in email that is sent by passing a custom function as the sendVerificationRequest option to Providers.Email().

e.g.

pages/api/auth/[...nextauth].js
providers: [
Providers.Email({
server: process.env.EMAIL_SERVER,
from: process.env.EMAIL_FROM,
sendVerificationRequest: ({ identifier: email, url, token, site, provider }) => { /* your function */ }
})
]

The following code shows the complete source for the built-in sendVerificationRequest() method:

import nodemailer from 'nodemailer'
const sendVerificationRequest = ({ identifier: email, url, token, baseUrl, provider }) => {
return new Promise((resolve, reject) => {
const { server, from } = provider
// Strip protocol from URL and use domain as site name
const site = baseUrl.replace(/^https?:\/\//, '')
nodemailer
.createTransport(server)
.sendMail({
to: email,
from,
subject: `Sign in to ${site}`,
text: text({ url, site, email }),
html: html({ url, site, email })
}, (error) => {
if (error) {
logger.error('SEND_VERIFICATION_EMAIL_ERROR', email, error)
return reject(new Error('SEND_VERIFICATION_EMAIL_ERROR', error))
}
return resolve()
})
})
}
// Email HTML body
const html = ({ url, site, email }) => {
// Insert invisible space into domains and email address to prevent both the
// email address and the domain from being turned into a hyperlink by email
// clients like Outlook and Apple mail, as this is confusing because it seems
// like they are supposed to click on their email address to sign in.
const escapedEmail = `${email.replace(/\./g, '​.')}`
const escapedSite = `${site.replace(/\./g, '​.')}`
// Some simple styling options
const backgroundColor = '#f9f9f9'
const textColor = '#444444'
const mainBackgroundColor = '#ffffff'
const buttonBackgroundColor = '#346df1'
const buttonBorderColor = '#346df1'
const buttonTextColor = '#ffffff'
// Uses tables for layout and inline CSS due to email client limitations
return `
<body style="background: ${backgroundColor};">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td align="center" style="padding: 10px 0px 20px 0px; font-size: 22px; font-family: Helvetica, Arial, sans-serif; color: ${textColor};">
<strong>${escapedSite}</strong>
</td>
</tr>
</table>
<table width="100%" border="0" cellspacing="20" cellpadding="0" style="background: ${mainBackgroundColor}; max-width: 600px; margin: auto; border-radius: 10px;">
<tr>
<td align="center" style="padding: 10px 0px 0px 0px; font-size: 18px; font-family: Helvetica, Arial, sans-serif; color: ${textColor};">
Sign in as <strong>${escapedEmail}</strong>
</td>
</tr>
<tr>
<td align="center" style="padding: 20px 0;">
<table border="0" cellspacing="0" cellpadding="0">
<tr>
<td align="center" style="border-radius: 5px;" bgcolor="${buttonBackgroundColor}"><a href="${url}" target="_blank" style="font-size: 18px; font-family: Helvetica, Arial, sans-serif; color: ${buttonTextColor}; text-decoration: none; text-decoration: none;border-radius: 5px; padding: 10px 20px; border: 1px solid ${buttonBorderColor}; display: inline-block; font-weight: bold;">Sign in</a></td>
</tr>
</table>
</td>
</tr>
<tr>
<td align="center" style="padding: 0px 0px 10px 0px; font-size: 16px; line-height: 22px; font-family: Helvetica, Arial, sans-serif; color: ${textColor};">
If you did not request this email you can safely ignore it.
</td>
</tr>
</table>
</body>
`
}
// Email text body – fallback for email clients that don't render HTML
const text = ({ url, site }) => `Sign in to ${site}\n${url}\n\n`
tip

If you want to generate great looking email client compatible HTML with React, check out https://mjml.io