refactor: use built in smtp library

go.mod

@@ -4,7 +4,6 @@ module message-pusher
 go 1.18
 
 require (
-	github.com/gin-contrib/gzip v0.0.6
 	github.com/gin-contrib/sessions v0.0.5
 	github.com/gin-contrib/static v0.0.1
 	github.com/gin-gonic/gin v1.9.0
@@ -12,9 +11,9 @@ require (
 	github.com/go-redis/redis/v8 v8.11.5
 	github.com/google/uuid v1.3.0
 	github.com/gorilla/websocket v1.5.0
+	github.com/tidwall/gjson v1.14.4
 	github.com/yuin/goldmark v1.5.3
 	golang.org/x/crypto v0.5.0
-	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df
 	gorm.io/driver/mysql v1.4.3
 	gorm.io/driver/sqlite v1.4.3
 	gorm.io/gorm v1.24.0
@@ -45,7 +44,6 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.0.6 // indirect
-	github.com/tidwall/gjson v1.14.4 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
@@ -55,6 +53,5 @@ require (
 	golang.org/x/sys v0.5.0 // indirect
 	golang.org/x/text v0.7.0 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
-	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )