feat: add set text plain and use premailer to set css inline

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@v4
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.20'
+          go-version: '1.23'
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v8
         with:
@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: ['1.20', '1.21', '1.22', '1.23']
+        go-version: ['1.23', '1.24']
     steps:
     - name: Checkout code
       uses: actions/checkout@v4
@@ -41,7 +41,7 @@ jobs:
         go mod download
     - name: Test
       run: |
-          go test -cover -race ./... -coverprofile=coverage.text
+          go test -v -cover -race ./... -coverprofile=coverage.text
     - name: Upload coverage reports to Codecov
       uses: codecov/codecov-action@v5
       with:

Makefile

@@ -1,6 +1,6 @@
 COVERAGE_FILE := coverage.out
 COVERAGE_HTML := coverage.html
-MIN_COVERAGE  := 80
+MIN_COVERAGE  := 90
 
 # Format code
 .PHONY: fmt
@@ -25,7 +25,7 @@ install:
 .PHONY: test
 test:
 	@echo "Running tests..."
-	go test -cover -race ./... -coverprofile=$(COVERAGE_FILE) -coverpkg=./...
+	go test -v -cover -race ./... -coverprofile=$(COVERAGE_FILE) -coverpkg=./...
 
 .PHONY: coverage
 coverage:

README.md

@@ -14,6 +14,7 @@ Go-Mailer is a Go library that wraps the [wneessen/go-mail](https://github.com/w
 - Attachment Support: Easily attach files from local disk, embedded filesystems, IOFS filesystems, or `io.Reader`/`io.ReadSeeker`.
 - Customizable Email Content: Allows setting greetings, salutations, and product information for a personalized experience.
 - Responsive HTML Template: Automatically formats emails with a clean, responsive design compatible with most email clients.
+- CSS-inlined HTML: Automatically inlines CSS styles for better compatibility with email clients that strip out `<style>` tags.
 
 ## Installation
 To install Go-Mailer, run the following command:
@@ -50,7 +51,11 @@ func main() {
 
     // Initialize the Go-Mailer instance with the existing client
     m := mailer.New(client,
-        mailer.WithFrom("noreply@example.com")
+        mailer.WithFrom("noreply@example.com"),
+        mailer.WithProduct(mailer.Product{
+            Name: "My Application",
+            URL:  "https://example.com",
+        })
     )
 
     // Build an HTML email using the fluent message builder
@@ -72,81 +77,16 @@ func main() {
 ## Fluent HTML Message Builder
 The fluent HTML message builder provides a chainable API to construct HTML emails intuitively. Key methods include:
 
-- `Subject(string)`: Sets the email subject.
-- `To(string)`: Adds a recipient email address.
-- `Cc(string)`: Adds a CC recipient email address.
-- `Bcc(string)`: Adds a BCC recipient email address.
-- `Line(string)`: Adds a plain text line to the email body.
-- `Linef(string, ...interface{})`: Adds a formatted line to the email body.
 - `Action(string, string)`: Adds a clickable button with a label and URL.
 - `Greeting(string)`: Sets a greeting line at the top of the email.
-- `Salutation(string)`: Sets a salutation line at the bottom of the email.
+- `Line(string)`: Adds a plain text line to the email body.
+- `Linef(string, ...interface{})`: Adds a formatted line to the email body.
 - `Product(mailer.Product)`: Sets product information for the email, which can be used in the footer.
-- `AttachFile(string, ...mailer.FileOption)`: Attaches a file from the local disk.
-- `AttachFromEmbedFS(string, *embed.FS, ...mailer.FileOption)`: Attaches a file from an embedded filesystem.
-- `AttachFromIOFS(string, fs.FS, ...mailer.FileOption)`: Attaches a file from an IOFS filesystem.
-- `AttachReader(string, io.Reader, ...mailer.FileOption)`: Attaches a file from an `io.Reader`.
-- `AttachReadSeeker(string, io.ReadSeeker, ...mailer.FileOption)`: Attaches a file from an `io.ReadSeeker`.
+- `Salutation(string)`: Sets a salutation line at the bottom of the email.
+- `Theme(string)`: Sets the theme for the email. Supported themes are "default" and "plain".
 
 The builder automatically formats the email with a clean, responsive HTML template, ensuring compatibility with most email clients.
-
-Example of a more complex email:
-
-```go
-message := mailer.NewMessage().
-    Subject("Welcome to Our Platform").
-    To("user@example.com").
-    Line("Thank you for signing up!").
-    Action("Activate Account", "https://example.com/activate").
-    Line("We're excited to have you on board.")
-```
-
-## Configuration
-Go-Mailer uses an existing `mail.Client` from `wneessen/go-mail`, which must be configured separately. The `mailer.New` function accepts optional configuration options for additional customization (e.g., default sender, reply-to address, etc.). Example configuration for the underlying `go-mail` client:
-
-```go
-client, err := mail.NewClient("smtp.sendgrid.net",
-    mail.WithPort(587),
-    mail.WithSMTPAuth(mail.SMTPAuthPlain),
-    mail.WithUsername("apikey"),
-    mail.WithPassword("your-sendgrid-api-key"),
-)
-if err != nil {
-    panic(err)
-}
-
-m := mailer.New(client,
-    mailer.WithFrom("noreply@example.com"),
-    mailer.WithReplyTo("support@example.com"),
-    mailer.WithProduct(mailer.Product{
-        Name: "Go Mailer",
-        URL: "https://github.com/ahmadfaizk/go-mailer",
-    })
-)
-```
-
-## Dependencies
-Go-Mailer relies on the following key dependency:
-- [wneessen/go-mail](https://github.com/wneessen/go-mail): Provides the core email sending functionality with support for SMTP, STARTTLS, and advanced features like DKIM and S/MIME.
-
-## Contributing
-Contributions are welcome! To contribute to Go-Mailer:
-
-1. Fork the repository
-2. Create a new branch (`git checkout -b feature/your-feature`)
-3. Make your changes
-4. Commit your changes (`git commit -m 'Add your feature'`)
-5. Push to the branch (`git push origin feature/your-feature`)
-6. Open a pull request
-
-Please ensure your code adheres to the project's coding standards and includes tests.
+The HTML template is based on [Postmark Transactional Email Templates](https://github.com/ActiveCampaign/postmark-templates).
 
 ## License
-This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.
-
-## Acknowledgements
-- [wneessen/go-mail](https://github.com/wneessen/go-mail) for providing the robust foundation for this library.
-- All contributors to the `go-mail` project for their excellent work.
-
-## Contact
-For questions or feedback, reach out to the maintainer at [ahmadfaizk's GitHub profile](https://github.com/ahmadfaizk).
+This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.

config.go

@@ -1,6 +1,7 @@
 package mailer
 
 type config struct {
+	theme   string
 	from    Address
 	replyTo string
 	product Product
@@ -33,12 +34,21 @@ func WithReplyTo(replyTo string) Option {
 	}
 }
 
+// WithTheme sets the theme for the email messages sent by the Mailer.
+// Supported themes are "default" and "plain".
+func WithTheme(theme string) Option {
+	return func(c *config) {
+		c.theme = theme
+	}
+}
+
 func newConfig(opts ...Option) *config {
 	cfg := &config{
 		product: Product{
 			Name: "GoMailer",
 			URL:  "https://github.com/ahmadfaizk/go-mailer",
 		},
+		theme: "default",
 	}
 	for _, opt := range opts {
 		opt(cfg)

go.mod

@@ -1,17 +1,23 @@
 module github.com/ahmadfaizk/go-mailer
 
-go 1.20
+go 1.23.0
 
 require (
 	github.com/mocktools/go-smtp-mock/v2 v2.5.1
 	github.com/stretchr/testify v1.10.0
+	github.com/vanng822/go-premailer v1.25.0
 	github.com/wneessen/go-mail v0.6.2
 )
 
 require (
+	github.com/PuerkitoBio/goquery v1.10.3 // indirect
+	github.com/andybalholm/cascadia v1.3.3 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/gorilla/css v1.0.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/crypto v0.33.0 // indirect
-	golang.org/x/text v0.22.0 // indirect
+	github.com/vanng822/css v1.0.1 // indirect
+	golang.org/x/crypto v0.39.0 // indirect
+	golang.org/x/net v0.41.0 // indirect
+	golang.org/x/text v0.26.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,7 +1,13 @@
+github.com/PuerkitoBio/goquery v1.10.3 h1:pFYcNSqHxBD06Fpj/KsbStFRsgRATgnf3LeXiUkhzPo=
+github.com/PuerkitoBio/goquery v1.10.3/go.mod h1:tMUX0zDMHXYlAQk6p35XxQMqMweEKB7iK7iLNd4RH4Y=
+github.com/andybalholm/cascadia v1.3.3 h1:AG2YHrzJIm4BZ19iwJ/DAua6Btl3IwJX+VI4kktS1LM=
+github.com/andybalholm/cascadia v1.3.3/go.mod h1:xNd9bqTn98Ln4DwST8/nG+H0yuB8Hmgu1YHNnWw0GeA=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/gorilla/css v1.0.1 h1:ntNaBIghp6JmvWnxbZKANoLyuXTPZ4cAMlo6RyhlbO8=
+github.com/gorilla/css v1.0.1/go.mod h1:BvnYkspnSzMmwRK+b8/xgNPLiIuNZr6vbZBTPQ2A3b0=
 github.com/mocktools/go-smtp-mock/v2 v2.5.1 h1:QcMJMChSgG1olVj4o6xxQFdrWzRjYNrcq660HAjd0wA=
 github.com/mocktools/go-smtp-mock/v2 v2.5.1/go.mod h1:Rr8M2njlxx//l5INl2+uESnsL2lDsL24teEykCrGfmE=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -16,6 +22,10 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/vanng822/css v1.0.1 h1:10yiXc4e8NI8ldU6mSrWmSWMuyWgPr9DZ63RSlsgDw8=
+github.com/vanng822/css v1.0.1/go.mod h1:tcnB1voG49QhCrwq1W0w5hhGasvOg+VQp9i9H1rCM1w=
+github.com/vanng822/go-premailer v1.25.0 h1:hGHKfroCXrCDTyGVR8o4HCON5/HWvc7C1uocS+VnaZs=
+github.com/vanng822/go-premailer v1.25.0/go.mod h1:8WJKIPZtegxqSOA8+eDFx7QNesKmMYfGEIodLTJqrtM=
 github.com/wneessen/go-mail v0.6.2 h1:c6V7c8D2mz868z9WJ+8zDKtUyLfZ1++uAZmo2GRFji8=
 github.com/wneessen/go-mail v0.6.2/go.mod h1:L/PYjPK3/2ZlNb2/FjEBIn9n1rUWjW+Toy531oVmeb4=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
@@ -24,8 +34,10 @@ golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5y
 golang.org/x/crypto v0.13.0/go.mod h1:y6Z2r+Rw4iayiXXAIxJIDAJ1zMW4yaTpebo8fPOliYc=
 golang.org/x/crypto v0.19.0/go.mod h1:Iy9bg/ha4yyC70EfRS8jz+B6ybOBKMaSxLj6P6oBDfU=
 golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
-golang.org/x/crypto v0.33.0 h1:IOBPskki6Lysi0lo9qQvbxiQ+FvsCC/YWOecCHAixus=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
 golang.org/x/crypto v0.33.0/go.mod h1:bVdXmD7IV/4GdElGPozy6U7lWdRXA4qyRVGJV57uQ5M=
+golang.org/x/crypto v0.39.0 h1:SHs+kF4LP+f+p14esP5jAoDpHU8Gu/v9lFRK6IT5imM=
+golang.org/x/crypto v0.39.0/go.mod h1:L+Xg3Wf6HoL4Bn4238Z6ft6KfEpN0tJGo53AAPC632U=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
@@ -39,12 +51,16 @@ golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
 golang.org/x/net v0.21.0/go.mod h1:bIjVDfnllIU7BJ2DNgfnXvpSvtn8VRwhlsaeUTyUS44=
 golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
+golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4=
+golang.org/x/net v0.41.0 h1:vBTly1HeNPEn3wtREYfy4GZ/NECgw2Cnl+nK6Nz3uvw=
+golang.org/x/net v0.41.0/go.mod h1:B/K4NNqkfmg07DQYrbwvSluqCJOOXwUjeb/5lOisjbA=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
 golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sync v0.11.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -56,6 +72,7 @@ golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/telemetry v0.0.0-20240228155512-f48c80bd79b2/go.mod h1:TeRTkGYfJXctD9OcfyVLyj2J3IxLnKwHJR8f4D8a3YE=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -65,6 +82,7 @@ golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
 golang.org/x/term v0.12.0/go.mod h1:owVbMEjm3cBLCHdkQu9b1opXd4ETQWc3BhuQGKgXgvU=
 golang.org/x/term v0.17.0/go.mod h1:lLRBjIVuehSbZlaOtGMbcMncT+aqLLLmKrsjNrUguwk=
 golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
+golang.org/x/term v0.27.0/go.mod h1:iMsnZpn0cago0GOrHO2+Y7u7JPn5AylBrcoWkElMTSM=
 golang.org/x/term v0.29.0/go.mod h1:6bl4lRlvVuDgSf3179VpIxBF0o10JUpXWOnI7nErv7s=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -74,8 +92,10 @@ golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.13.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/text v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 golang.org/x/text v0.22.0/go.mod h1:YRoo4H8PVmsu+E3Ou7cqLVH8oXWIHVoX0jqUWALQhfY=
+golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
+golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

mailer.go

@@ -33,20 +33,25 @@ func (m *Mailer) SendContext(ctx context.Context, message *Message) error {
 	return m.client.DialAndSendWithContext(ctx, msg)
 }
 
-func (m *Mailer) toMailMsg(message *Message) (*mail.Msg, error) {
+func (m *Mailer) validateAndModifyMessage(message *Message) error {
 	if message == nil {
-		return nil, errors.New("message cannot be nil")
+		return errors.New("message cannot be nil")
 	}
 	if len(message.GetTo()) == 0 {
-		return nil, errors.New("message must have at least one recipient")
+		return errors.New("message must have at least one recipient")
 	}
 	if message.GetSubject() == "" {
-		return nil, errors.New("message must have a subject")
+		return errors.New("message must have a subject")
 	}
 
 	message.Product(m.cfg.product)
-	html, err := message.GenerateHTML()
-	if err != nil {
+	message.Theme(m.cfg.theme)
+
+	return nil
+}
+
+func (m *Mailer) toMailMsg(message *Message) (*mail.Msg, error) {
+	if err := m.validateAndModifyMessage(message); err != nil {
 		return nil, err
 	}
 
@@ -83,6 +88,16 @@ func (m *Mailer) toMailMsg(message *Message) (*mail.Msg, error) {
 		}
 	}
 	msg.Subject(message.GetSubject())
+
+	plaintext, err := message.GeneratePlaintext()
+	if err != nil {
+		return nil, err
+	}
+	msg.SetBodyString(mail.TypeTextPlain, plaintext)
+	html, err := message.GenerateHTML()
+	if err != nil {
+		return nil, err
+	}
 	msg.SetBodyString(mail.TypeTextHTML, html)
 
 	if err := m.setAttachments(msg, message); err != nil {

mailer_test.go

@@ -33,10 +33,10 @@ func TestNew(t *testing.T) {
 			opts: []mailer.Option{
 				mailer.WithFrom("Test Sender", "test@example.com"),
 				mailer.WithProduct(mailer.Product{
-					Name:    "Test Product",
-					LogoURL: "https://example.com/logo.png",
-					URL:     "https://example.com",
+					Name: "Test Product",
+					URL:  "https://example.com",
 				}),
+				mailer.WithReplyTo("reply@example.com"),
 			},
 			wantNil: false,
 		},
@@ -86,7 +86,7 @@ func TestMailer_Send(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	mailMailer := mailer.New(client, mailer.WithFrom("noreply@example.com"))
+	mailMailer := mailer.New(client, mailer.WithFrom("noreply@example.com", "No Reply"))
 
 	tests := []struct {
 		name        string
@@ -305,6 +305,18 @@ func TestMailer_Send(t *testing.T) {
 			wantErr:     true,
 			errContains: "failed to parse mail address",
 		},
+		{
+			name: "return errors when reply-to email is invalid",
+			message: func() *mailer.Message {
+				msg := mailer.NewMessage().
+					To("recipient@example.com").
+					ReplyTo("invalid-email").
+					Subject("Test Subject")
+				return msg
+			}(),
+			wantErr:     true,
+			errContains: "failed to parse reply-to address",
+		},
 		{
 			name: "return errors when attachment embedded file is not found",
 			message: func() *mailer.Message {