diff --git a/internal/smtpd/forward.go b/internal/smtpd/forward.go
index 7f7978c..98fe9cf 100644
--- a/internal/smtpd/forward.go
+++ b/internal/smtpd/forward.go
@@ -4,6 +4,7 @@ import (
 	"crypto/tls"
 	"fmt"
 	"net/smtp"
+	"os"
 	"strings"
 
 	"github.com/axllent/mailpit/config"
@@ -60,6 +61,13 @@ func createForwardingSMTPClient(config config.SMTPForwardConfigStruct, addr stri
 		}
 	}
 
+	// Set the hostname for HELO/EHLO
+	if hostname, err := os.Hostname(); err == nil {
+		if err := client.Hello(hostname); err != nil {
+			return nil, fmt.Errorf("error saying HELO/EHLO to %s: %v", addr, err)
+		}
+	}
+
 	// Note: The caller is responsible for closing the client
 	return client, nil
 }
diff --git a/internal/smtpd/relay.go b/internal/smtpd/relay.go
index 66c2829..5e94b0a 100644
--- a/internal/smtpd/relay.go
+++ b/internal/smtpd/relay.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/smtp"
+	"os"
 	"strings"
 
 	"github.com/axllent/mailpit/config"
@@ -94,6 +95,13 @@ func createRelaySMTPClient(config config.SMTPRelayConfigStruct, addr string) (*s
 		}
 	}
 
+	// Set the hostname for HELO/EHLO
+	if hostname, err := os.Hostname(); err == nil {
+		if err := client.Hello(hostname); err != nil {
+			return nil, fmt.Errorf("error saying HELO/EHLO to %s: %v", addr, err)
+		}
+	}
+
 	// Note: The caller is responsible for closing the client
 	return client, nil
 }