Large mail messenger overhaul w/ swap to wneessen/go-mail

go.mod

@@ -8,7 +8,6 @@ require (
 	github.com/BurntSushi/toml v1.4.0
 	github.com/KimMachineGun/automemlimit v0.7.0
 	github.com/PuerkitoBio/goquery v1.10.1
-	github.com/Shopify/gomail v0.0.0-20220729171026-0784ece65e69
 	github.com/araddon/dateparse v0.0.0-20210429162001-6b43995a97de
 	github.com/avast/retry-go/v4 v4.6.0
 	github.com/blang/semver/v4 v4.0.0
@@ -33,6 +32,7 @@ require (
 	github.com/rs/zerolog v1.33.0
 	github.com/slack-go/slack v0.15.0
 	github.com/tj/go-spin v1.1.0
+	github.com/wneessen/go-mail v0.6.0
 	go.uber.org/automaxprocs v1.6.0
 	go.uber.org/goleak v1.3.0
 	go.uber.org/ratelimit v0.3.1
@@ -94,6 +94,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20250106144421-5f5ef82da422 // indirect
 	google.golang.org/grpc v1.69.2 // indirect
 	google.golang.org/protobuf v1.36.2 // indirect
-	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -12,8 +12,6 @@ github.com/KimMachineGun/automemlimit v0.7.0 h1:7G06p/dMSf7G8E6oq+f2uOPuVncFyIlD
 github.com/KimMachineGun/automemlimit v0.7.0/go.mod h1:QZxpHaGOQoYvFhv/r4u3U0JTC2ZcOwbSr11UZF46UBM=
 github.com/PuerkitoBio/goquery v1.10.1 h1:Y8JGYUkXWTGRB6Ars3+j3kN0xg1YqqlwvdTV8WTFQcU=
 github.com/PuerkitoBio/goquery v1.10.1/go.mod h1:IYiHrOMps66ag56LEH7QYDDupKXyo5A8qrjIx3ZtujY=
-github.com/Shopify/gomail v0.0.0-20220729171026-0784ece65e69 h1:gPoXdwo3sKq8qcfMu/Nc/wkJMLKwe7kaG9Uo8tOj3cU=
-github.com/Shopify/gomail v0.0.0-20220729171026-0784ece65e69/go.mod h1:RS+Gaowa0M+gCuiFAiRMGBCMqxLrNA7TESTU/Wbblm8=
 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/araddon/dateparse v0.0.0-20210429162001-6b43995a97de h1:FxWPpzIjnTlhPwqqXc4/vE0f7GvRjuAsbW+HOIe8KnA=
@@ -218,6 +216,8 @@ github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
 github.com/ugorji/go/codec v1.2.12 h1:9LC83zGrHhuUA9l16C9AHXAqEV/2wBQ4nkvumAE65EE=
 github.com/ugorji/go/codec v1.2.12/go.mod h1:UNopzCgEMSXjBc6AOMqYvWC1ktqTAfzJZUZgYf6w6lg=
+github.com/wneessen/go-mail v0.6.0 h1:wO7EeJ8RL6DD+aycFGntil6b11g3FNQpQQQC1gkm97Y=
+github.com/wneessen/go-mail v0.6.0/go.mod h1:G702XlFhzHV0Z4w9j2VsH5K9dJDvj0hx+yOOp1oX9vc=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
 go.opencensus.io v0.24.0/go.mod h1:vNK8G9p7aAivkbmorf4v+7Hgx+Zs0yY+0fOtgBfjQKo=
@@ -322,6 +322,7 @@ 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 v0.28.0/go.mod h1:Sw/lC2IAUZ92udQNf3WodGtn4k/XoLyZoh8v/8uiwek=
 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=
@@ -373,13 +374,9 @@ google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpAD
 google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
 google.golang.org/protobuf v1.36.2 h1:R8FeyR1/eLmkutZOM5CWghmo5itiG9z0ktFlTVLuTmU=
 google.golang.org/protobuf v1.36.2/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
-gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc h1:2gGKlE2+asNV9m7xrywl36YYNnBG5ZQ0r/BOOxqPpmk=
-gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc/go.mod h1:m7x9LTH6d71AHyAX77c9yqWCCa3UKHcVEj9y7hAtKDk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
-gopkg.in/mail.v2 v2.3.1 h1:WYFn/oANrAGP2C0dcV6/pbkPzv8yGzqTjPmTeO7qoXk=
-gopkg.in/mail.v2 v2.3.1/go.mod h1:htwXN1Qh09vZJ1NVKxQqHPBaCBbzKhp5GzuJEA4VJWw=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

messenger/mail.go

@@ -27,11 +27,11 @@ import (
 	"strconv"
 	"time"
 
-	mail "github.com/Shopify/gomail"
 	"github.com/avast/retry-go/v4"
 	"github.com/dkorunic/e-dnevnik-bot/format"
 	"github.com/dkorunic/e-dnevnik-bot/logger"
 	"github.com/dkorunic/e-dnevnik-bot/msgtypes"
+	mail "github.com/wneessen/go-mail"
 	"go.uber.org/ratelimit"
 )
 
@@ -43,8 +43,9 @@ const (
 )
 
 var (
-	ErrMailSendingMessage = errors.New("error sending mail message")
-	ErrMailInvalidPort    = errors.New("invalid or missing SMTP port, will try with default 587/tcp")
+	ErrMailInvalidPort     = errors.New("invalid or missing SMTP port, will try with default 587/tcp")
+	ErrMailDialer          = errors.New("failed to create mail delivery client")
+	ErrMailSendingMessages = errors.New("error sending mail messages")
 )
 
 // Mail sends a message through the mail service.
@@ -92,40 +93,58 @@ func Mail(ctx context.Context, ch <-chan interface{}, server, port, username, pa
 			htmlContent := format.HTMLMsg(g.Username, g.Subject, g.IsExam, g.Descriptions, g.Fields)
 
 			// establish dialer
-			d := mail.NewDialer(server, portInt, username, password)
-			d.StartTLSPolicy = mail.OpportunisticStartTLS
+			d, err := mail.NewClient(server,
+				mail.WithPort(portInt),
+				mail.WithSMTPAuth(mail.SMTPAuthPlain),
+				mail.WithTLSPolicy(mail.TLSOpportunistic),
+				mail.WithUsername(username),
+				mail.WithPassword(password),
+			)
+			if err != nil {
+				logger.Error().Msgf("%v: %v", ErrMailDialer, err)
+
+				break
+			}
+
+			var messages []*mail.Msg
 
-			// send to all recipients
+			// bulk send to all recipients
 			for _, u := range to {
-				m := mail.NewMessage()
-				m.SetHeader("From", from)
-				m.SetHeader("To", u)
+				m := mail.NewMsg()
+				_ = m.From(from)
+				_ = m.To(u)
+
+				m.SetMessageID()
+				m.SetDate()
+				m.SetBulk()
 
 				if subject != "" {
-					m.SetHeader("Subject", subject)
+					m.Subject(subject)
 				} else {
-					m.SetHeader("Subject", MailSubject)
+					m.Subject(MailSubject)
 				}
 
-				m.SetBody("text/plain", plainContent)
-				m.AddAlternative("text/html", htmlContent)
+				m.SetBodyString(mail.TypeTextPlain, plainContent)
+				m.SetBodyString(mail.TypeTextHTML, htmlContent)
 
-				rl.Take()
-
-				// retryable and cancellable attempt to send a message
-				err = retry.Do(
-					func() error {
-						return d.DialAndSend(m)
-					},
-					retry.Attempts(retries),
-					retry.Context(ctx),
-					retry.Delay(MailMinDelay),
-				)
-				if err != nil {
-					logger.Error().Msgf("%v: %v", ErrMailSendingMessage, err)
+				messages = append(messages, m)
+			}
 
-					break
-				}
+			rl.Take()
+
+			// retryable and cancellable attempt to send a message
+			err = retry.Do(
+				func() error {
+					return d.DialAndSend(messages...)
+				},
+				retry.Attempts(retries),
+				retry.Context(ctx),
+				retry.Delay(MailMinDelay),
+			)
+			if err != nil {
+				logger.Error().Msgf("%v: %v", ErrMailSendingMessages, err)
+
+				break
 			}
 		}
 	}