diff --git a/install b/install
index a78a4bf..5110186 100755
--- a/install
+++ b/install
@@ -579,6 +579,7 @@ config_boulder() {
 
     mkdir -p "cmd/mail-tester"
     cp $cloneDir/mail-tester.go cmd/mail-tester/main.go
+    perl -i -p0e "s/(\n\t\"github.com\/letsencrypt\/boulder\/cmd\")/\t_ \"github.com\/letsencrypt\/boulder\/cmd\/mail-tester\"\n\t\1/igs"  cmd/boulder/main.go &>>$installLog
 
     sudo -u labca -H patch -p1 < $cloneDir/patches/db_migrations.patch &>>$installLog
     cp sa/_db/migrations/20210223140000_CombinedSchema.sql "$boulderLabCADir/.backup/"
diff --git a/mail-tester.go b/mail-tester.go
index 3658f21..7e23c18 100644
--- a/mail-tester.go
+++ b/mail-tester.go
@@ -1,4 +1,4 @@
-package main
+package notmain
 
 import (
 	"flag"
@@ -25,19 +25,38 @@ args:
 type config struct {
 	Mailer struct {
 		cmd.ServiceConfig
-		cmd.DBConfig
+		DB cmd.DBConfig
 		cmd.SMTPConfig
 
 		From    string
 		Subject string
 
+		CertLimit int
+		NagTimes  []string
+		// How much earlier (than configured nag intervals) to
+		// send reminders, to account for the expected delay
+		// before the next expiration-mailer invocation.
+		NagCheckInterval string
+		// Path to a text/template email template
+		EmailTemplate string
+
+		Frequency cmd.ConfigDuration
+
+		TLS       cmd.TLSConfig
+		SAService *cmd.GRPCClientConfig
+
 		DNSTries     int
 		DNSResolvers []string
 
+		// Path to a file containing a list of trusted root certificates for use
+		// during the SMTP connection (as opposed to the gRPC connections).
+		SMTPTrustedRootFile string
+
 		Features map[string]bool
 	}
 
 	Syslog cmd.SyslogConfig
+	Beeline cmd.BeelineConfig
 
 	Common struct {
 		DNSResolver               string
@@ -54,13 +73,13 @@ func main() {
 
 	configFile := flag.String("config", "", "File path to the configuration file for this service")
 	flag.Parse()
-	args := flag.Args()
-	recipient := args[0]
-
 	if len(os.Args) <= 3 || *configFile == "" {
 		usage()
 	}
 
+	args := flag.Args()
+	recipient := args[0]
+
 	var c config
 	err := cmd.ReadConfigFile(*configFile, &c)
 	cmd.FailOnError(err, "Reading JSON config file into config structure")
@@ -126,3 +145,7 @@ func main() {
 	err = mailClient.SendMail(recipients, "Test Email from LabCA", "Test sending email from the LabCA server")
 	cmd.FailOnError(err, "mail-tester has failed")
 }
+
+func init() {
+	cmd.RegisterCommand("mail-tester", main)
+}