refactoring, created email package

bot/command.go

@@ -10,6 +10,7 @@ import (
 	"maunium.net/go/mautrix/format"
 	"maunium.net/go/mautrix/id"
 
+	"gitlab.com/etke.cc/postmoogle/email"
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
@@ -415,7 +416,7 @@ func (b *Bot) runSend(ctx context.Context) {
 	tos := strings.Split(to, ",")
 	// validate first
 	for _, to := range tos {
-		if !utils.AddressValid(to) {
+		if !email.AddressValid(to) {
 			b.Error(ctx, evt.RoomID, "email address is not valid")
 			return
 		}
@@ -426,10 +427,10 @@ func (b *Bot) runSend(ctx context.Context) {
 
 	domain := utils.SanitizeDomain(cfg.Domain())
 	from := mailbox + "@" + domain
-	ID := utils.MessageID(evt.ID, domain)
+	ID := email.MessageID(evt.ID, domain)
 	for _, to := range tos {
-		email := utils.NewEmail(ID, "", " "+ID, subject, from, to, body, htmlBody, nil)
+		eml := email.New(ID, "", " "+ID, subject, from, to, body, htmlBody, nil)
-		data := email.Compose(b.getBotSettings().DKIMPrivateKey())
+		data := eml.Compose(b.getBotSettings().DKIMPrivateKey())
 		if data == "" {
 			b.SendError(ctx, evt.RoomID, "email body is empty")
 			return
@@ -437,14 +438,14 @@ func (b *Bot) runSend(ctx context.Context) {
 		queued, err := b.Sendmail(evt.ID, from, to, data)
 		if queued {
 			b.log.Error("cannot send email: %v", err)
-			b.saveSentMetadata(ctx, queued, evt.ID, email, &cfg)
+			b.saveSentMetadata(ctx, queued, evt.ID, eml, &cfg)
 			continue
 		}
 		if err != nil {
 			b.Error(ctx, evt.RoomID, "cannot send email to %s: %v", to, err)
 			continue
 		}
-		b.saveSentMetadata(ctx, false, evt.ID, email, &cfg)
+		b.saveSentMetadata(ctx, false, evt.ID, eml, &cfg)
 	}
 	if len(tos) > 1 {
 		b.SendNotice(ctx, evt.RoomID, "All emails were sent.")

bot/email.go

@@ -9,6 +9,7 @@ import (
 	"maunium.net/go/mautrix/format"
 	"maunium.net/go/mautrix/id"
 
+	"gitlab.com/etke.cc/postmoogle/email"
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
@@ -85,7 +86,7 @@ func (b *Bot) GetMapping(mailbox string) (id.RoomID, bool) {
 }
 
 // GetIFOptions returns incoming email filtering options (room settings)
-func (b *Bot) GetIFOptions(roomID id.RoomID) utils.IncomingFilteringOptions {
+func (b *Bot) GetIFOptions(roomID id.RoomID) email.IncomingFilteringOptions {
 	cfg, err := b.getRoomSettings(roomID)
 	if err != nil {
 		b.log.Error("cannot retrieve room settings: %v", err)
@@ -96,7 +97,7 @@ func (b *Bot) GetIFOptions(roomID id.RoomID) utils.IncomingFilteringOptions {
 }
 
 // IncomingEmail sends incoming email to matrix room
-func (b *Bot) IncomingEmail(ctx context.Context, email *utils.Email) error {
+func (b *Bot) IncomingEmail(ctx context.Context, email *email.Email) error {
 	roomID, ok := b.GetMapping(email.Mailbox(true))
 	if !ok {
 		return errors.New("room not found")
@@ -177,11 +178,11 @@ func (b *Bot) SendEmailReply(ctx context.Context) {
 	body := content.Body
 	htmlBody := content.FormattedBody
 
-	meta.MessageID = utils.MessageID(evt.ID, domain)
+	meta.MessageID = email.MessageID(evt.ID, domain)
 	meta.References = meta.References + " " + meta.MessageID
 	b.log.Debug("send email reply: %+v", meta)
-	email := utils.NewEmail(meta.MessageID, meta.InReplyTo, meta.References, meta.Subject, meta.From, meta.To, body, htmlBody, nil)
+	eml := email.New(meta.MessageID, meta.InReplyTo, meta.References, meta.Subject, meta.From, meta.To, body, htmlBody, nil)
-	data := email.Compose(b.getBotSettings().DKIMPrivateKey())
+	data := eml.Compose(b.getBotSettings().DKIMPrivateKey())
 	if data == "" {
 		b.SendError(ctx, evt.RoomID, "email body is empty")
 		return
@@ -190,7 +191,7 @@ func (b *Bot) SendEmailReply(ctx context.Context) {
 	queued, err := b.Sendmail(evt.ID, meta.From, meta.To, data)
 	if queued {
 		b.log.Error("cannot send email: %v", err)
-		b.saveSentMetadata(ctx, queued, meta.ThreadID, email, &cfg)
+		b.saveSentMetadata(ctx, queued, meta.ThreadID, eml, &cfg)
 		return
 	}
 
@@ -199,7 +200,7 @@ func (b *Bot) SendEmailReply(ctx context.Context) {
 		return
 	}
 
-	b.saveSentMetadata(ctx, queued, meta.ThreadID, email, &cfg)
+	b.saveSentMetadata(ctx, queued, meta.ThreadID, eml, &cfg)
 }
 
 type parentEmail struct {
@@ -259,7 +260,7 @@ func (b *Bot) getParentEmail(evt *event.Event, domain string) parentEmail {
 		return parent
 	}
 
-	parent.MessageID = utils.MessageID(parentEvt.ID, domain)
+	parent.MessageID = email.MessageID(parentEvt.ID, domain)
 	parent.From = utils.EventField[string](&parentEvt.Content, eventFromKey)
 	parent.To = utils.EventField[string](&parentEvt.Content, eventToKey)
 	parent.InReplyTo = utils.EventField[string](&parentEvt.Content, eventMessageIDkey)
@@ -283,14 +284,14 @@ func (b *Bot) getParentEmail(evt *event.Event, domain string) parentEmail {
 
 // saveSentMetadata used to save metadata from !pm sent and thread reply events to a separate notice message
 // because that metadata is needed to determine email thread relations
-func (b *Bot) saveSentMetadata(ctx context.Context, queued bool, threadID id.EventID, email *utils.Email, cfg *roomSettings) {
+func (b *Bot) saveSentMetadata(ctx context.Context, queued bool, threadID id.EventID, eml *email.Email, cfg *roomSettings) {
-	text := "Email has been sent to " + email.To
+	text := "Email has been sent to " + eml.RcptTo
 	if queued {
-		text = "Email to " + email.To + " has been queued"
+		text = "Email to " + eml.RcptTo + " has been queued"
 	}
 
 	evt := eventFromContext(ctx)
-	content := email.Content(threadID, cfg.ContentOptions())
+	content := eml.Content(threadID, cfg.ContentOptions())
 	notice := format.RenderMarkdown(text, true, true)
 	msgContent, ok := content.Parsed.(*event.MessageEventContent)
 	if !ok {
@@ -307,8 +308,8 @@ func (b *Bot) saveSentMetadata(ctx context.Context, queued bool, threadID id.Eve
 		return
 	}
 	domain := utils.SanitizeDomain(cfg.Domain())
-	b.setThreadID(evt.RoomID, utils.MessageID(evt.ID, domain), threadID)
+	b.setThreadID(evt.RoomID, email.MessageID(evt.ID, domain), threadID)
-	b.setThreadID(evt.RoomID, utils.MessageID(msgID, domain), threadID)
+	b.setThreadID(evt.RoomID, email.MessageID(msgID, domain), threadID)
 	b.setLastEventID(evt.RoomID, threadID, msgID)
 }
 

bot/settings_room.go

@@ -5,6 +5,7 @@ import (
 
 	"maunium.net/go/mautrix/id"
 
+	"gitlab.com/etke.cc/postmoogle/email"
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
@@ -143,8 +144,8 @@ func (s roomSettings) migrateSpamlistSettings() {
 }
 
 // ContentOptions converts room display settings to content options
-func (s roomSettings) ContentOptions() *utils.ContentOptions {
+func (s roomSettings) ContentOptions() *email.ContentOptions {
-	return &utils.ContentOptions{
+	return &email.ContentOptions{
 		HTML:      !s.NoHTML(),
 		Sender:    !s.NoSender(),
 		Recipient: !s.NoRecipient(),

email/email.go

@@ -1,31 +1,20 @@
-package utils
+package email
 
 import (
 	"crypto"
 	"crypto/x509"
 	"encoding/pem"
-	"fmt"
-	"net/mail"
-	"regexp"
 	"strings"
-	"time"
 
 	"github.com/emersion/go-msgauth/dkim"
 	"github.com/jhillyerd/enmime"
 	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/format"
 	"maunium.net/go/mautrix/id"
+
+	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
-var styleRegex = regexp.MustCompile("<style((.|\n|\r)*?)<\\/style>")
-
-// IncomingFilteringOptions for incoming mail
-type IncomingFilteringOptions interface {
-	SpamcheckSMTP() bool
-	SpamcheckMX() bool
-	Spamlist() []string
-}
-
 // Email object
 type Email struct {
 	Date       string
@@ -39,54 +28,13 @@ type Email struct {
 	Subject    string
 	Text       string
 	HTML       string
-	Files      []*File
+	Files      []*utils.File
 }
 
-// ContentOptions represents settings that specify how an email is to be converted to a Matrix message
+// New constructs Email object
-type ContentOptions struct {
+func New(messageID, inReplyTo, references, subject, from, to, text, html string, files []*utils.File) *Email {
-	// On/Off
-	Sender    bool
-	Recipient bool
-	Subject   bool
-	HTML      bool
-	Threads   bool
-
-	// Keys
-	MessageIDKey  string
-	InReplyToKey  string
-	ReferencesKey string
-	SubjectKey    string
-	FromKey       string
-	ToKey         string
-	CcKey         string
-	RcptToKey     string
-}
-
-// AddressValid checks if email address is valid
-func AddressValid(email string) bool {
-	_, err := mail.ParseAddress(email)
-	return err == nil
-}
-
-// EmailDate returns Date in RFC1123 with numeric timezone
-func EmailDate(original ...time.Time) string {
-	now := time.Now().UTC()
-	if len(original) > 0 && !original[0].IsZero() {
-		now = original[0]
-	}
-
-	return now.Format(time.RFC1123Z)
-}
-
-// MessageID generates email Message-Id from matrix event ID
-func MessageID(eventID id.EventID, domain string) string {
-	return fmt.Sprintf("<%s@%s>", eventID, domain)
-}
-
-// NewEmail constructs Email object
-func NewEmail(messageID, inReplyTo, references, subject, from, to, text, html string, files []*File) *Email {
 	email := &Email{
-		Date:       EmailDate(),
+		Date:       dateNow(),
 		MessageID:  messageID,
 		InReplyTo:  inReplyTo,
 		References: references,
@@ -107,35 +55,33 @@ func NewEmail(messageID, inReplyTo, references, subject, from, to, text, html st
 	return email
 }
 
-func FromEnvelope(rcptto string, eml *enmime.Envelope) *Email {
+// FromEnvelope constructs Email object from envelope
-	datetime, _ := eml.Date() //nolint:errcheck // handled in EmailDate()
+func FromEnvelope(rcptto string, envelope *enmime.Envelope) *Email {
-	date := EmailDate(datetime)
+	datetime, _ := envelope.Date() //nolint:errcheck // handled in dateNow()
+	date := dateNow(datetime)
 
 	var html string
-	if eml.HTML != "" {
+	if envelope.HTML != "" {
-		html = styleRegex.ReplaceAllString(eml.HTML, "")
+		html = styleRegex.ReplaceAllString(envelope.HTML, "")
 	}
 
-	files := make([]*File, 0, len(eml.Attachments))
+	files := make([]*utils.File, 0, len(envelope.Attachments))
-	for _, attachment := range eml.Attachments {
+	for _, attachment := range envelope.Attachments {
-		for _, err := range attachment.Errors {
+		file := utils.NewFile(attachment.FileName, attachment.Content)
-			log.Warn("attachment error: %v", err)
-		}
-		file := NewFile(attachment.FileName, attachment.Content)
 		files = append(files, file)
 	}
 
 	email := &Email{
 		Date:       date,
-		MessageID:  eml.GetHeader("Message-Id"),
+		MessageID:  envelope.GetHeader("Message-Id"),
-		InReplyTo:  eml.GetHeader("In-Reply-To"),
+		InReplyTo:  envelope.GetHeader("In-Reply-To"),
-		References: eml.GetHeader("References"),
+		References: envelope.GetHeader("References"),
-		From:       eml.GetHeader("From"),
+		From:       envelope.GetHeader("From"),
-		To:         eml.GetHeader("To"),
+		To:         envelope.GetHeader("To"),
 		RcptTo:     rcptto,
-		CC:         eml.GetHeader("Cc"),
+		CC:         envelope.GetHeader("Cc"),
-		Subject:    eml.GetHeader("Subject"),
+		Subject:    envelope.GetHeader("Subject"),
-		Text:       eml.Text,
+		Text:       envelope.Text,
 		HTML:       html,
 		Files:      files,
 	}
@@ -146,9 +92,9 @@ func FromEnvelope(rcptto string, eml *enmime.Envelope) *Email {
 // Mailbox returns postmoogle's mailbox, parsing it from FROM (if incoming=false) or TO (incoming=true)
 func (e *Email) Mailbox(incoming bool) string {
 	if incoming {
-		return Mailbox(e.RcptTo)
+		return utils.Mailbox(e.RcptTo)
 	}
-	return Mailbox(e.From)
+	return utils.Mailbox(e.From)
 }
 
 // Content converts the email object to a Matrix event content
@@ -176,7 +122,7 @@ func (e *Email) Content(threadID id.EventID, options *ContentOptions) *event.Con
 	}
 
 	parsed := format.RenderMarkdown(text.String(), true, true)
-	parsed.RelatesTo = RelatesTo(options.Threads, threadID)
+	parsed.RelatesTo = utils.RelatesTo(options.Threads, threadID)
 
 	content := event.Content{
 		Raw: map[string]interface{}{
@@ -222,13 +168,11 @@ func (e *Email) Compose(privkey string) string {
 
 	root, err := mail.Build()
 	if err != nil {
-		log.Error("cannot compose email: %v", err)
 		return ""
 	}
 	var data strings.Builder
 	err = root.Encode(&data)
 	if err != nil {
-		log.Error("cannot encode email: %v", err)
 		return ""
 	}
 

email/options.go

@@ -0,0 +1,28 @@
+package email
+
+// IncomingFilteringOptions for incoming mail
+type IncomingFilteringOptions interface {
+	SpamcheckSMTP() bool
+	SpamcheckMX() bool
+	Spamlist() []string
+}
+
+// ContentOptions represents settings that specify how an email is to be converted to a Matrix message
+type ContentOptions struct {
+	// On/Off
+	Sender    bool
+	Recipient bool
+	Subject   bool
+	HTML      bool
+	Threads   bool
+
+	// Keys
+	MessageIDKey  string
+	InReplyToKey  string
+	ReferencesKey string
+	SubjectKey    string
+	FromKey       string
+	ToKey         string
+	CcKey         string
+	RcptToKey     string
+}

email/utils.go

@@ -0,0 +1,33 @@
+package email
+
+import (
+	"fmt"
+	"net/mail"
+	"regexp"
+	"time"
+
+	"maunium.net/go/mautrix/id"
+)
+
+var styleRegex = regexp.MustCompile("<style((.|\n|\r)*?)<\\/style>")
+
+// AddressValid checks if email address is valid
+func AddressValid(email string) bool {
+	_, err := mail.ParseAddress(email)
+	return err == nil
+}
+
+// MessageID generates email Message-Id from matrix event ID
+func MessageID(eventID id.EventID, domain string) string {
+	return fmt.Sprintf("<%s@%s>", eventID, domain)
+}
+
+// dateNow returns Date in RFC1123 with numeric timezone
+func dateNow(original ...time.Time) string {
+	now := time.Now().UTC()
+	if len(original) > 0 && !original[0].IsZero() {
+		now = original[0]
+	}
+
+	return now.Format(time.RFC1123Z)
+}

go.mod

@@ -22,7 +22,6 @@ require (
 	gitlab.com/etke.cc/go/trysmtp v1.0.0
 	gitlab.com/etke.cc/go/validator v1.0.4
 	gitlab.com/etke.cc/linkpearl v0.0.0-20221116205701-65547c5608e6
-	golang.org/x/net v0.2.0
 	maunium.net/go/mautrix v0.12.3
 )
 
@@ -49,6 +48,7 @@ require (
 	github.com/tidwall/sjson v1.2.5 // indirect
 	github.com/yuin/goldmark v1.5.3 // indirect
 	golang.org/x/crypto v0.3.0 // indirect
+	golang.org/x/net v0.2.0 // indirect
 	golang.org/x/sys v0.2.0 // indirect
 	golang.org/x/text v0.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect

smtp/manager.go

@@ -11,7 +11,7 @@ import (
 	"gitlab.com/etke.cc/go/logger"
 	"maunium.net/go/mautrix/id"
 
-	"gitlab.com/etke.cc/postmoogle/utils"
+	"gitlab.com/etke.cc/postmoogle/email"
 )
 
 type Config struct {
@@ -45,8 +45,8 @@ type matrixbot interface {
 	IsBanned(net.Addr) bool
 	Ban(net.Addr)
 	GetMapping(string) (id.RoomID, bool)
-	GetIFOptions(id.RoomID) utils.IncomingFilteringOptions
+	GetIFOptions(id.RoomID) email.IncomingFilteringOptions
-	IncomingEmail(context.Context, *utils.Email) error
+	IncomingEmail(context.Context, *email.Email) error
 	SetSendmail(func(string, string, string) error)
 	GetDKIMprivkey() string
 }

smtp/server.go

@@ -10,7 +10,7 @@ import (
 	"gitlab.com/etke.cc/go/logger"
 	"gitlab.com/etke.cc/go/trysmtp"
 
-	"gitlab.com/etke.cc/postmoogle/utils"
+	"gitlab.com/etke.cc/postmoogle/email"
 )
 
 var (
@@ -41,7 +41,7 @@ func (m *mailServer) Login(state *smtp.ConnectionState, username, password strin
 		return nil, ErrBanned
 	}
 
-	if !utils.AddressValid(username) {
+	if !email.AddressValid(username) {
 		m.log.Debug("address %s is invalid", username)
 		m.bot.Ban(state.RemoteAddr)
 		return nil, ErrBanned
@@ -114,6 +114,6 @@ func (m *mailServer) SendEmail(from, to, data string) error {
 }
 
 // ReceiveEmail - incoming mail into matrix room
-func (m *mailServer) ReceiveEmail(ctx context.Context, email *utils.Email) error {
+func (m *mailServer) ReceiveEmail(ctx context.Context, eml *email.Email) error {
-	return m.bot.IncomingEmail(ctx, email)
+	return m.bot.IncomingEmail(ctx, eml)
 }

smtp/session.go

@@ -13,6 +13,7 @@ import (
 	"gitlab.com/etke.cc/go/validator"
 	"maunium.net/go/mautrix/id"
 
+	"gitlab.com/etke.cc/postmoogle/email"
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
@@ -20,8 +21,8 @@ import (
 type incomingSession struct {
 	log          *logger.Logger
 	getRoomID    func(string) (id.RoomID, bool)
-	getFilters   func(id.RoomID) utils.IncomingFilteringOptions
+	getFilters   func(id.RoomID) email.IncomingFilteringOptions
-	receiveEmail func(context.Context, *utils.Email) error
+	receiveEmail func(context.Context, *email.Email) error
 	greylisted   func(net.Addr) bool
 	ban          func(net.Addr)
 	domains      []string
@@ -34,7 +35,7 @@ type incomingSession struct {
 
 func (s *incomingSession) Mail(from string, opts smtp.MailOptions) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("from", from)
-	if !utils.AddressValid(from) {
+	if !email.AddressValid(from) {
 		s.log.Debug("address %s is invalid", from)
 		s.ban(s.addr)
 		return ErrBanned
@@ -84,15 +85,15 @@ func (s *incomingSession) Data(r io.Reader) error {
 		}
 	}
 	parser := enmime.NewParser()
-	eml, err := parser.ReadEnvelope(r)
+	envelope, err := parser.ReadEnvelope(r)
 	if err != nil {
 		return err
 	}
 
-	email := utils.FromEnvelope(s.tos[0], eml)
+	eml := email.FromEnvelope(s.tos[0], envelope)
 	for _, to := range s.tos {
-		email.RcptTo = to
+		eml.RcptTo = to
-		err := s.receiveEmail(s.ctx, email)
+		err := s.receiveEmail(s.ctx, eml)
 		if err != nil {
 			return err
 		}
@@ -116,7 +117,7 @@ type outgoingSession struct {
 
 func (s *outgoingSession) Mail(from string, opts smtp.MailOptions) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("from", from)
-	if !utils.AddressValid(from) {
+	if !email.AddressValid(from) {
 		return errors.New("please, provide email address")
 	}
 	return nil
@@ -132,14 +133,14 @@ func (s *outgoingSession) Rcpt(to string) error {
 
 func (s *outgoingSession) Data(r io.Reader) error {
 	parser := enmime.NewParser()
-	eml, err := parser.ReadEnvelope(r)
+	envelope, err := parser.ReadEnvelope(r)
 	if err != nil {
 		return err
 	}
-	email := utils.FromEnvelope(s.tos[0], eml)
+	eml := email.FromEnvelope(s.tos[0], envelope)
 	for _, to := range s.tos {
-		email.RcptTo = to
+		eml.RcptTo = to
-		err := s.sendmail(email.From, to, email.Compose(s.privkey))
+		err := s.sendmail(eml.From, to, eml.Compose(s.privkey))
 		if err != nil {
 			return err
 		}
@@ -150,7 +151,7 @@ func (s *outgoingSession) Data(r io.Reader) error {
 func (s *outgoingSession) Reset()        {}
 func (s *outgoingSession) Logout() error { return nil }
 
-func validateEmail(from, to string, log *logger.Logger, options utils.IncomingFilteringOptions) bool {
+func validateEmail(from, to string, log *logger.Logger, options email.IncomingFilteringOptions) bool {
 	enforce := validator.Enforce{
 		Email: true,
 		MX:    options.SpamcheckMX(),

utils/mail.go

@@ -0,0 +1,41 @@
+package utils
+
+import "strings"
+
+// Mailbox returns mailbox part from email address
+func Mailbox(email string) string {
+	index := strings.LastIndex(email, "@")
+	if index == -1 {
+		return email
+	}
+	return email[:index]
+}
+
+// EmailsList returns human-readable list of mailbox's emails for all available domains
+func EmailsList(mailbox string, domain string) string {
+	var msg strings.Builder
+	domain = SanitizeDomain(domain)
+	msg.WriteString(mailbox)
+	msg.WriteString("@")
+	msg.WriteString(domain)
+
+	count := len(domains) - 1
+	for i, aliasDomain := range domains {
+		if i < count {
+			msg.WriteString(", ")
+		}
+		if aliasDomain == domain {
+			continue
+		}
+		msg.WriteString(mailbox)
+		msg.WriteString("@")
+		msg.WriteString(aliasDomain)
+	}
+
+	return msg.String()
+}
+
+// Hostname returns hostname part from email address
+func Hostname(email string) string {
+	return email[strings.LastIndex(email, "@")+1:]
+}

utils/utils.go

@@ -22,44 +22,6 @@ func SetDomains(slice []string) {
 	domains = slice
 }
 
-// Mailbox returns mailbox part from email address
-func Mailbox(email string) string {
-	index := strings.LastIndex(email, "@")
-	if index == -1 {
-		return email
-	}
-	return email[:index]
-}
-
-// EmailsList returns human-readable list of mailbox's emails for all available domains
-func EmailsList(mailbox string, domain string) string {
-	var msg strings.Builder
-	domain = SanitizeDomain(domain)
-	msg.WriteString(mailbox)
-	msg.WriteString("@")
-	msg.WriteString(domain)
-
-	count := len(domains) - 1
-	for i, aliasDomain := range domains {
-		if i < count {
-			msg.WriteString(", ")
-		}
-		if aliasDomain == domain {
-			continue
-		}
-		msg.WriteString(mailbox)
-		msg.WriteString("@")
-		msg.WriteString(aliasDomain)
-	}
-
-	return msg.String()
-}
-
-// Hostname returns hostname part from email address
-func Hostname(email string) string {
-	return email[strings.LastIndex(email, "@")+1:]
-}
-
 // SanitizeDomain checks that input domain is available for use
 func SanitizeDomain(domain string) string {
 	domain = strings.TrimSpace(domain)