diff --git a/internal/auth/dovecot_sasl/dovecot_sasl.go b/internal/auth/dovecot_sasl/dovecot_sasl.go
index 9f6990d..50cac2e 100644
--- a/internal/auth/dovecot_sasl/dovecot_sasl.go
+++ b/internal/auth/dovecot_sasl/dovecot_sasl.go
@@ -118,6 +118,7 @@ func (a *Auth) AuthPlain(username, password string) error {
 		if err != nil {
 			return err
 		}
+		defer a.returnConn(cl)
 
 		// Pretend it is SMTP even though we really don't know.
 		// We also have no connection information to pass to the server...
@@ -128,6 +129,7 @@ func (a *Auth) AuthPlain(username, password string) error {
 		if err != nil {
 			return err
 		}
+		defer a.returnConn(cl)
 
 		// Pretend it is SMTP even though we really don't know.
 		return cl.Do("SMTP", sasl.NewLoginClient(username, password))