diff --git a/email.go b/email.go
new file mode 100644
index 0000000..024d4cd
--- /dev/null
+++ b/email.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"os"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/resendlabs/resend-go"
+)
+
+// sendEmailSuccessMsg is the tea.Msg handled by Bubble Tea when the email has
+// been sent successfully.
+type sendEmailSuccessMsg struct{}
+
+// sendEmailFailureMsg is the tea.Msg handled by Bubble Tea when the email has
+// failed to send.
+type sendEmailFailureMsg error
+
+// sendEmailCmd returns a tea.Cmd that sends the email.
+func (m Model) sendEmailCmd() tea.Cmd {
+	return func() tea.Msg {
+		attachments := make([]string, len(m.Attachments.Items()))
+		for i, a := range m.Attachments.Items() {
+			at, ok := a.(attachment)
+			if !ok {
+				continue
+			}
+			attachments[i] = string(at)
+		}
+		err := sendEmail(m.From.Value(), m.To.Value(), m.Subject.Value(), m.Body.Value(), attachments)
+		if err != nil {
+			return sendEmailFailureMsg(err)
+		}
+		return sendEmailSuccessMsg{}
+	}
+}
+
+func sendEmail(from, to, subject, body string, attachments []string) error {
+	client := resend.NewClient(os.Getenv(RESEND_API_KEY))
+
+	request := &resend.SendEmailRequest{
+		From:    from,
+		To:      []string{to},
+		Subject: subject,
+		Html:    body,
+	}
+
+	_, err := client.Emails.Send(request)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/go.mod b/go.mod
index 86744f4..6a35f40 100644
--- a/go.mod
+++ b/go.mod
@@ -4,8 +4,9 @@ go 1.19
 
 require (
 	github.com/charmbracelet/bubbles v0.16.1
-	github.com/charmbracelet/bubbletea v0.24.3-0.20230609163353-b80eb8303bba
+	github.com/charmbracelet/bubbletea v0.24.3-0.20230614142509-c0cc6aa1fb4f
 	github.com/charmbracelet/lipgloss v0.7.1
+	github.com/resendlabs/resend-go v1.6.0
 	github.com/spf13/cobra v1.7.0
 	golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1
 )
@@ -28,7 +29,7 @@ require (
 	github.com/sahilm/fuzzy v0.1.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/sync v0.1.0 // indirect
-	golang.org/x/sys v0.6.0 // indirect
+	golang.org/x/sys v0.8.0 // indirect
 	golang.org/x/term v0.6.0 // indirect
 	golang.org/x/text v0.3.8 // indirect
 )
diff --git a/go.sum b/go.sum
index 4755189..090169d 100644
--- a/go.sum
+++ b/go.sum
@@ -4,13 +4,14 @@ github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiE
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
 github.com/charmbracelet/bubbles v0.16.1 h1:6uzpAAaT9ZqKssntbvZMlksWHruQLNxg49H5WdeuYSY=
 github.com/charmbracelet/bubbles v0.16.1/go.mod h1:2QCp9LFlEsBQMvIYERr7Ww2H2bA7xen1idUDIzm/+Xc=
-github.com/charmbracelet/bubbletea v0.24.3-0.20230609163353-b80eb8303bba h1:hWjlqzPiG3dWN5KZUAKKnqz/R8BlYqX1Aw+nk7riQss=
-github.com/charmbracelet/bubbletea v0.24.3-0.20230609163353-b80eb8303bba/go.mod h1:XdrNrV4J8GiyshTtx3DNuYkR1FDaJmO3l2nejekbsgg=
+github.com/charmbracelet/bubbletea v0.24.3-0.20230614142509-c0cc6aa1fb4f h1:piPKA2I5VF6qDNPoDxw33/1wr7C5AZV/nAziJ5P4pM8=
+github.com/charmbracelet/bubbletea v0.24.3-0.20230614142509-c0cc6aa1fb4f/go.mod h1:XdrNrV4J8GiyshTtx3DNuYkR1FDaJmO3l2nejekbsgg=
 github.com/charmbracelet/lipgloss v0.7.1 h1:17WMwi7N1b1rVWOjMT+rCh7sQkvDU75B2hbZpc5Kc1E=
 github.com/charmbracelet/lipgloss v0.7.1/go.mod h1:yG0k3giv8Qj8edTCbbg6AlQ5e8KNWpFujkNawKNhE2c=
 github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81 h1:q2hJAaP1k2wIvVRd/hEHD7lacgqrCPS+k8g1MndzfWY=
 github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81/go.mod h1:YynlIjWYF8myEu6sdkwKIvGQq+cOckRm6So2avqoYAk=
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -33,6 +34,9 @@ github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
 github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
 github.com/muesli/termenv v0.15.1 h1:UzuTb/+hhlBugQz28rpzey4ZuKcZ03MeKsoG7IJZIxs=
 github.com/muesli/termenv v0.15.1/go.mod h1:HeAQPTzpfs016yGtA4g00CsdYnVLJvxsS4ANqrZs2sQ=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/resendlabs/resend-go v1.6.0 h1:QnXJv71HVKHS+IDv9anK5XpYCegHH5MLK1W3q4cAvjk=
+github.com/resendlabs/resend-go v1.6.0/go.mod h1:yip1STH7Bqfm4fD0So5HgyNbt5taG5Cplc4xXxETyLI=
 github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
@@ -43,16 +47,19 @@ github.com/spf13/cobra v1.7.0 h1:hyqWnYt1ZQShIddO5kBpj3vu05/++x6tJ6dg8EC572I=
 github.com/spf13/cobra v1.7.0/go.mod h1:uLxZILRyS/50WlhOIKD7W6V5bgeIt+4sICxh6uRMrb0=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
 golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1 h1:k/i9J1pBpvlfR+9QsetwPyERsqu1GIbi967PQMq3Ivc=
 golang.org/x/exp v0.0.0-20230522175609-2e198f4a06a1/go.mod h1:V1LtkGg67GoY2N1AnLN78QLrzxkLyJw7RJb1gzOOz9w=
 golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.6.0 h1:clScbb1cHjoCkyRbWwBEUZ5H/tIFu5TAXIqaZD0Gcjw=
 golang.org/x/term v0.6.0/go.mod h1:m6U89DPEgQRMq3DNkDClhWw02AUbt2daBVO4cn4Hv9U=
 golang.org/x/text v0.3.8 h1:nAL+RVCQ9uMn3vJZbV+MRnydTJFPf8qqY42YiA6MrqY=
 golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/main.go b/main.go
index a6fa6f5..cd21f06 100644
--- a/main.go
+++ b/main.go
@@ -1,12 +1,15 @@
 package main
 
 import (
+	"fmt"
 	"os"
 
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/spf13/cobra"
 )
 
+const RESEND_API_KEY = "RESEND_API_KEY"
+
 var rootCmd = &cobra.Command{
 	Use:   "email",
 	Short: "email is a command line interface for sending emails.",
@@ -22,6 +25,13 @@ var rootCmd = &cobra.Command{
 }
 
 func main() {
+	key := os.Getenv(RESEND_API_KEY)
+	if key == "" {
+		fmt.Printf("\n  %s %s %s\n\n", errorHeaderStyle.String(), inlineCodeStyle.Render(RESEND_API_KEY), "environment variable is required.")
+		fmt.Printf("  %s %s\n\n", commentStyle.Render("You can grab one at"), linkStyle.Render("https://resend.com"))
+		os.Exit(1)
+	}
+
 	err := rootCmd.Execute()
 	if err != nil {
 		os.Exit(1)
diff --git a/model.go b/model.go
index c9752d9..3df21f2 100644
--- a/model.go
+++ b/model.go
@@ -51,6 +51,7 @@ type Model struct {
 	help           help.Model
 	keymap         KeyMap
 	quitting       bool
+	err            error
 }
 
 func NewModel() Model {
@@ -106,7 +107,7 @@ func NewModel() Model {
 	picker := filepicker.New()
 	picker.CurrentDirectory, _ = os.UserHomeDir()
 
-	loadingSpinner := spinner.NewModel()
+	loadingSpinner := spinner.New()
 	loadingSpinner.Spinner = spinner.Dot
 
 	return Model{
@@ -132,13 +133,12 @@ func (m Model) Init() tea.Cmd {
 
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	switch msg := msg.(type) {
-	case tea.WindowSizeMsg:
-		m.From.Width = msg.Width - 2
-		m.To.Width = msg.Width - 2
-		m.Subject.Width = msg.Width - 2
-		m.Body.SetWidth(msg.Width - 2)
-		m.Attachments.SetWidth(msg.Width - 2)
-
+	case sendEmailSuccessMsg:
+		m.quitting = true
+		return m, tea.Quit
+	case sendEmailFailureMsg:
+		m.state = editingFrom
+		m.err = msg
 	case tea.KeyMsg:
 		switch {
 		case key.Matches(msg, m.keymap.NextInput):
@@ -178,6 +178,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m.state = sendingEmail
 			return m, tea.Batch(
 				m.loadingSpinner.Tick,
+				m.sendEmailCmd(),
 			)
 		case key.Matches(msg, m.keymap.Attach):
 			m.state = pickingFile
@@ -295,6 +296,11 @@ func (m Model) View() string {
 	s.WriteString("\n")
 	s.WriteString(m.help.View(m.keymap))
 
+	if m.err != nil {
+		s.WriteString("\n\n")
+		s.WriteString(errorStyle.Render(m.err.Error()))
+	}
+
 	return paddedStyle.Render(s.String())
 }
 
diff --git a/style.go b/style.go
index c0edaff..619f3cc 100644
--- a/style.go
+++ b/style.go
@@ -19,4 +19,11 @@ var (
 	cursorStyle      = lipgloss.NewStyle().Foreground(whiteColor)
 
 	paddedStyle = lipgloss.NewStyle().Padding(1)
+
+	errorHeaderStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("#F1F1F1")).Background(lipgloss.Color("#FF5F87")).Bold(true).Padding(0, 1).SetString("ERROR")
+	errorStyle       = lipgloss.NewStyle().Foreground(lipgloss.Color("#FF5F87"))
+	commentStyle     = lipgloss.NewStyle().Foreground(lipgloss.Color("#757575"))
+
+	inlineCodeStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("#FF5F87")).Background(lipgloss.Color("#3A3A3A")).Padding(0, 1)
+	linkStyle       = lipgloss.NewStyle().Foreground(lipgloss.Color("#00AF87")).Underline(true)
 )