diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 10e96b4a2..7ffb6ef49 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -248,6 +248,7 @@ email_title = Email Settings
 smtp_addr = SMTP Host
 smtp_port = SMTP Port
 smtp_from = Send Email As
+smtp_from_invalid = The "Send Email As" address is invalid
 smtp_from_helper = Email address Forgejo will use. Enter a plain email address or use the "Name" <email@example.com> format.
 mailer_user = SMTP Username
 mailer_password = SMTP Password
diff --git a/routers/install/install.go b/routers/install/install.go
index 48271a64f..13504953c 100644
--- a/routers/install/install.go
+++ b/routers/install/install.go
@@ -7,6 +7,7 @@ package install
 import (
 	"fmt"
 	"net/http"
+	"net/mail"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -423,6 +424,11 @@ func SubmitInstall(ctx *context.Context) {
 	}
 
 	if len(strings.TrimSpace(form.SMTPAddr)) > 0 {
+		if _, err := mail.ParseAddress(form.SMTPFrom); err != nil {
+			ctx.RenderWithErr(ctx.Tr("install.smtp_from_invalid"), tplInstall, &form)
+			return
+		}
+
 		cfg.Section("mailer").Key("ENABLED").SetValue("true")
 		cfg.Section("mailer").Key("SMTP_ADDR").SetValue(form.SMTPAddr)
 		cfg.Section("mailer").Key("SMTP_PORT").SetValue(form.SMTPPort)