Why is ses.sendRawEmail sending the email, but it is not being received?

I am sending an email with sendRawEmail which contains a pdf as base64 as raw message data. When using a Base64 to PDF converter in the browser, it does return the correct pdf. However, when sending the email, the console logs a success with a messageId, but the email never gets received by the user. The email is correct, verified, and not in suppression.

// Request Data
const requestUserData = async () => {
    try {
        const htmlContent = `<h1>Hello</h1>`

        pdf.create(htmlContent).toBuffer((err, buffer) => {
            if (err) return console.error(err)
            sendEmailWithAttachment(
                ['toEmail'],
                buffer.toString('base64')
            )
        })

        console.log('done')
    } catch (err) {
        console.error(err)
    }
}

// Send With Attachment
const sendEmailWithAttachment = async (emails, buffer) => {
    // Set Up Email
    const params = {
        Source: `Name <email>`, // Sender's email address
        Destinations: emails,
        RawMessage: {
            Data: buffer,
        },
    }

    ses.sendRawEmail(params, (err, data) => {
        if (err) {
            console.log('Error:', err)
        } else {
            console.log('Email sent successfully:', data)
        }
    })
}

In case it is needed, the argument being passed to buffer in sendEmailWithAtatchment() is:

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