diff --git a/clanModules/deltachat.nix b/clanModules/deltachat.nix
index 66f3b0499..1f703db15 100644
--- a/clanModules/deltachat.nix
+++ b/clanModules/deltachat.nix
@@ -1,4 +1,5 @@
 { config, pkgs, ... }: {
+  networking.firewall.interfaces."zt+".allowedTCPPorts = [ 25 ]; # smtp with other hosts
   environment.systemPackages = [ pkgs.deltachat-desktop ];
 
   services.maddy = {