Here we send a signup confirmation email to a user.
import { getHTMLTemplate, fillHtmlTemplate, sendEmail } from "../email"
export const sendEmailConfirmationLink = async (
email: string,
authLink: string
) => {
const html = await getHTMLTemplate("auth")
await sendEmail({
email,
body: fillHtmlTemplate(html, {
"auth-link": authLink,
email,
}),
subject: "Log in to Increaser",
source: `Login <noreply@increaser.org>`,
})
}First, we want to take an HTML template. The function takes the template name and reads it from the file. I make template names the same as HtmlTemplate type.
export const getHTMLTemplate = memoize((template: HtmlTemplate) => {
return readFile(
path.resolve(__dirname, `../../templates/${template}.html`),
"utf8"
)
})I don't usually send emails with fancy styling to not appear in recipient spam or promotion tabs.
In the auth-email template, we expect two variables - auth-link and email.
<p>Click the link below to sign in to <b>Increaser</b>.</p>
<p>This link will expire in 20 minutes.</p>
<a href={{auth-link}}>Sign in to Increaser</a>
<p>Confirming this request will securely sign you in using {{email}}.</p>
- Increaser Team
Once we've read the file into a string we'll use the fillHtmlTemplate function to insert variables into an email html.
export const fillHtmlTemplate = (
html: string,
variables: Record<string, string>
) => {
let result = html
Object.entries(variables).forEach(([key, value]) => {
result = result.split(`{{${key}}}`).join(value)
})
return result
}We pass the recipient email, HTML body, subject, and source to the sendEmail function.
I ran my Lambda in the European region, but AWS SES doesn't work there. So I explicitly pass the Virginia region to the SES constructor.
interface SendEmailParameters {
email: string
body: string
subject: string
source: string
}
const ses = new aws.SES({ region: "us-east-1" })
export const sendEmail = ({
email,
body,
subject,
source,
}: SendEmailParameters) =>
ses
.sendEmail({
Destination: {
ToAddresses: [email],
},
Message: {
Body: {
Html: {
Data: body,
},
},
Subject: {
Data: subject,
},
},
Source: source,
})
.promise()We pass Destination, Message, and Source to the SES method and make it into a promise.