diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fdc37b9..ff1c34f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
     name: Lint/Test
     strategy:
       matrix:
-        go-version: [1.17.x]
+        go-version: [1.22.x]
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:
@@ -41,21 +41,12 @@ jobs:
         run: |
           export GOPATH=$HOME/go
           export PATH=$PATH:$GOPATH/bin
-          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.31.0
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.54.2
           make lint
 
       - name: Run Unit tests
         run: |
           make test
-      - name: Install goveralls
-        env:
-          GO111MODULE: off
-        run: go get github.com/mattn/goveralls
-      - name: Send coverage
-        env:
-          COVERALLS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: goveralls -coverprofile=covprofile -service=github
-
 
 
 
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 3bd76e5..b60f845 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: 'https://github.com/golangci/golangci-lint'
-    rev: v1.46.2
+    rev: v1.54.2
     hooks:
       - id: golangci-lint
         entry: golangci-lint run
diff --git a/cmd/apiserver/main.go b/cmd/apiserver/main.go
index 582ebc7..1331905 100644
--- a/cmd/apiserver/main.go
+++ b/cmd/apiserver/main.go
@@ -5,9 +5,11 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"time"
 
-	emailVerifier "github.com/AfterShip/email-verifier"
 	"github.com/julienschmidt/httprouter"
+
+	emailVerifier "github.com/AfterShip/email-verifier"
 )
 
 func GetEmailVerification(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
@@ -37,5 +39,12 @@ func main() {
 
 	router.GET("/v1/:email/verification", GetEmailVerification)
 
-	log.Fatal(http.ListenAndServe(":8080", router))
+	server := &http.Server{
+		Addr:         ":8080",
+		Handler:      router,
+		ReadTimeout:  30 * time.Second,
+		WriteTimeout: 30 * time.Second,
+	}
+
+	log.Fatal(server.ListenAndServe())
 }
diff --git a/cmd/build_metadata/main.go b/cmd/build_metadata/main.go
index 1d92b17..009216f 100644
--- a/cmd/build_metadata/main.go
+++ b/cmd/build_metadata/main.go
@@ -5,7 +5,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -19,7 +18,7 @@ func writeFile(filePath string, data []byte) {
 	}
 
 	fmt.Printf("Writing new %s\n", filePath)
-	err := ioutil.WriteFile(filePath, data, os.FileMode(0664))
+	err := os.WriteFile(filePath, data, os.FileMode(0664))
 	if err != nil {
 		log.Fatalf("Error writing '%s': %s", filePath, err)
 	}
@@ -115,7 +114,7 @@ func updateMetaData() {
 	if err = cmd.Start(); err != nil {
 		log.Fatalf("error executing update.sh to update meta data: %s", err.Error())
 	}
-	data, err := ioutil.ReadAll(stderr)
+	data, err := io.ReadAll(stderr)
 	if err != nil {
 		log.Fatalf("error reading update.sh result: %s : %s", err.Error(), data)
 	}
diff --git a/go.mod b/go.mod
index 1ba3dfd..b0de3d2 100644
--- a/go.mod
+++ b/go.mod
@@ -1,13 +1,21 @@
 module github.com/AfterShip/email-verifier
 
-go 1.15
+go 1.22
 
 require (
 	github.com/hbollon/go-edlib v1.6.0
 	github.com/julienschmidt/httprouter v1.3.0
-	github.com/kr/pretty v0.2.1 // indirect
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/net v0.19.0
-	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/h2non/gock.v1 v1.1.2
 )
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 // indirect
+	github.com/kr/pretty v0.2.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/go.sum b/go.sum
index 32b33aa..e25797e 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,3 @@
-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/h2non/parth v0.0.0-20190131123155-b4df798d6542 h1:2VTzZjLZBgl62/EtslCrtky5vbi9dd7HrQPQIx6wqiw=
@@ -16,59 +15,16 @@ github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 h1:W6apQkHrMkS0Muv8G/TipAy
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
-golang.org/x/crypto v0.16.0/go.mod h1:gCAAfMLgwOJRpTjQ2zCCt2OcSfYMTeZVSRtQlPC7Nq4=
-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/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
-golang.org/x/net v0.10.0/go.mod h1:0qNGK6F8kojg2nk9dLZ2mShWaEBan6FAoqfSigmmuDg=
 golang.org/x/net v0.19.0 h1:zTwKpTd2XuCqf8huc7Fo2iSy+4RHPd10s4KzeTnVr1c=
 golang.org/x/net v0.19.0/go.mod h1:CfAk/cbD4CthTvqiEl8NpboMuiuOYsAr/7NOjZJtv1U=
-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/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=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
-golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
-golang.org/x/term v0.15.0/go.mod h1:BDl952bC7+uMoWR75FIrCDx79TPU9oHkTZ9yRbYOrX0=
-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=
-golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-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=
-golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/h2non/gock.v1 v1.1.2 h1:jBbHXgGBK/AoPVfJh5x4r/WxIrElvbLel8TCZkkZJoY=
 gopkg.in/h2non/gock.v1 v1.1.2/go.mod h1:n7UGz/ckNChHiK05rDoiC4MYSunEC/lyaUm2WWaDva0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 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/gravatar.go b/gravatar.go
index 14b373a..891c9f7 100644
--- a/gravatar.go
+++ b/gravatar.go
@@ -2,7 +2,7 @@ package emailverifier
 
 import (
 	"context"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -10,8 +10,8 @@ import (
 
 // Gravatar is detail about the Gravatar
 type Gravatar struct {
-	HasGravatar bool   // whether has gravatar
-	GravatarUrl string // gravatar url
+	HasGravatar bool   `json:"has_gravatar"` // whether has gravatar
+	GravatarUrl string `json:"gravatar_url"` // gravatar url
 }
 
 // CheckGravatar will return the Gravatar records for the given email.
@@ -36,7 +36,7 @@ func (v *Verifier) CheckGravatar(email string) (*Gravatar, error) {
 		_ = resp.Body.Close()
 	}()
 
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
diff --git a/handler.go b/handler.go
index 434aa1b..d63ca88 100644
--- a/handler.go
+++ b/handler.go
@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"time"
 )
@@ -30,7 +30,7 @@ func updateDisposableDomains(source string) error {
 
 	var domains []string
 
-	content, err := ioutil.ReadAll(resp.Body)
+	content, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return err
 	}
diff --git a/smtp_by_api.go b/smtp_by_api.go
index 2d73d2b..2bf2db1 100644
--- a/smtp_by_api.go
+++ b/smtp_by_api.go
@@ -1,7 +1,6 @@
 package emailverifier
 
 const (
-	GMAIL = "gmail"
 	YAHOO = "yahoo"
 )
 
diff --git a/smtp_by_api_gmail.go b/smtp_by_api_gmail.go
deleted file mode 100644
index b173afa..0000000
--- a/smtp_by_api_gmail.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package emailverifier
-
-import (
-	"context"
-	"fmt"
-	"net/http"
-	"strings"
-	"time"
-)
-
-const (
-	glxuPageFormat = "https://mail.google.com/mail/gxlu?email=%s"
-)
-
-// See the link below to know why we can use this way to check if a gmail exists.
-// https://blog.0day.rocks/abusing-gmail-to-get-previously-unlisted-e-mail-addresses-41544b62b2
-func newGmailAPIVerifier(client *http.Client) smtpAPIVerifier {
-	if client == nil {
-		client = http.DefaultClient
-	}
-	return gmail{
-		client: client,
-	}
-}
-
-type gmail struct {
-	client *http.Client
-}
-
-func (g gmail) isSupported(host string) bool {
-	return strings.HasSuffix(host, ".google.com.")
-}
-
-func (g gmail) check(domain, username string) (*SMTP, error) {
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	defer cancel()
-	email := fmt.Sprintf("%s@%s", username, domain)
-	request, err := http.NewRequestWithContext(ctx, http.MethodGet, fmt.Sprintf(glxuPageFormat, email), nil)
-	if err != nil {
-		return nil, err
-	}
-	resp, err := g.client.Do(request)
-	if err != nil {
-		return &SMTP{}, err
-	}
-	defer resp.Body.Close()
-	emailExists := len(resp.Cookies()) > 0
-
-	return &SMTP{
-		HostExists:  true,
-		Deliverable: emailExists,
-	}, nil
-}
diff --git a/smtp_by_api_gmail_test.go b/smtp_by_api_gmail_test.go
deleted file mode 100644
index fc76332..0000000
--- a/smtp_by_api_gmail_test.go
+++ /dev/null
@@ -1,25 +0,0 @@
-package emailverifier
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestGmailCheckByAPI(t *testing.T) {
-	gmailAPIVerifier := newGmailAPIVerifier(nil)
-
-	t.Run("email exists", func(tt *testing.T) {
-		res, err := gmailAPIVerifier.check("gmail.com", "someone")
-		assert.NoError(t, err)
-		assert.Equal(t, true, res.HostExists)
-		assert.Equal(t, true, res.Deliverable)
-	})
-	t.Run("invalid email not exists", func(tt *testing.T) {
-		// username must greater than 6 characters
-		res, err := gmailAPIVerifier.check("gmail.com", "hello")
-		assert.NoError(t, err)
-		assert.Equal(t, true, res.HostExists)
-		assert.Equal(t, false, res.Deliverable)
-	})
-}
diff --git a/smtp_by_api_yahoo.go b/smtp_by_api_yahoo.go
index 5e0119c..4b76751 100644
--- a/smtp_by_api_yahoo.go
+++ b/smtp_by_api_yahoo.go
@@ -5,7 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"regexp"
 	"strings"
@@ -142,7 +142,7 @@ func (y yahoo) sendValidateRequest(req yahooValidateReq) (yahooErrorResp, error)
 		return res, err
 	}
 	defer resp.Body.Close()
-	respBytes, err := ioutil.ReadAll(resp.Body)
+	respBytes, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return res, err
 	}
@@ -162,7 +162,7 @@ func (y yahoo) toSignUpPage() ([]*http.Cookie, []byte, error) {
 		return nil, nil, err
 	}
 	defer resp.Body.Close()
-	respBytes, err := ioutil.ReadAll(resp.Body)
+	respBytes, err := io.ReadAll(resp.Body)
 	return resp.Cookies(), respBytes, err
 }
 
diff --git a/smtp_test.go b/smtp_test.go
index f9495da..12a6332 100644
--- a/smtp_test.go
+++ b/smtp_test.go
@@ -21,24 +21,6 @@ func TestCheckSMTPOK_ByApi(t *testing.T) {
 		username string
 		expected *SMTP
 	}{
-		{
-			name:     "gmail exists",
-			domain:   "gmail.com",
-			username: "someone",
-			expected: &SMTP{
-				HostExists:  true,
-				Deliverable: true,
-			},
-		},
-		{
-			name:     "gmail no exists",
-			domain:   "gmail.com",
-			username: "hello",
-			expected: &SMTP{
-				HostExists:  true,
-				Deliverable: false,
-			},
-		},
 		{
 			name:     "yahoo exists",
 			domain:   "yahoo.com",
@@ -76,9 +58,7 @@ func TestCheckSMTPOK_ByApi(t *testing.T) {
 			},
 		},
 	}
-	_ = verifier.EnableAPIVerifier(GMAIL)
 	_ = verifier.EnableAPIVerifier(YAHOO)
-	defer verifier.DisableAPIVerifier(GMAIL)
 	defer verifier.DisableAPIVerifier(YAHOO)
 	for _, c := range cases {
 		test := c
diff --git a/verifier.go b/verifier.go
index 2ede140..192f85e 100644
--- a/verifier.go
+++ b/verifier.go
@@ -145,8 +145,6 @@ func (v *Verifier) EnableSMTPCheck() *Verifier {
 // If you use this feature in a production environment, please ensure that you have sufficient backup measures in place, as this may encounter rate limiting or other API issues.
 func (v *Verifier) EnableAPIVerifier(name string) error {
 	switch name {
-	case GMAIL:
-		v.apiVerifiers[GMAIL] = newGmailAPIVerifier(http.DefaultClient)
 	case YAHOO:
 		v.apiVerifiers[YAHOO] = newYahooAPIVerifier(http.DefaultClient)
 	default: