Show default EHLO

app/src/main/java/eu/faircode/email/EmailService.java

@@ -582,11 +582,8 @@ public class EmailService implements AutoCloseable {
                 }
 
         } else if ("smtp".equals(protocol) || "smtps".equals(protocol)) {
-            String[] c = BuildConfig.APPLICATION_ID.split("\\.");
-            Collections.reverse(Arrays.asList(c));
-            String hdomain = TextUtils.join(".", c);
-
             // https://tools.ietf.org/html/rfc5321#section-4.1.3
+            String hdomain = getDefaultEhlo();
             String haddr = (address instanceof Inet4Address ? "[127.0.0.1]" : "[IPv6:::1]");
 
             properties.put("mail." + protocol + ".localhost",
@@ -614,6 +611,12 @@ public class EmailService implements AutoCloseable {
             throw new NoSuchProviderException(protocol);
     }
 
+    static String getDefaultEhlo() {
+        String[] c = BuildConfig.APPLICATION_ID.split("\\.");
+        Collections.reverse(Arrays.asList(c));
+        return TextUtils.join(".", c);
+    }
+
     private static class ErrorHolder {
         AuthorizationException error;
     }

app/src/main/java/eu/faircode/email/FragmentIdentity.java

@@ -468,6 +468,8 @@ public class FragmentIdentity extends FragmentBase {
 
         btnAdvanced.setVisibility(View.GONE);
 
+        etEhlo.setHint(EmailService.getDefaultEhlo());
+
         btnSave.setVisibility(View.GONE);
         pbSave.setVisibility(View.GONE);
         cbTrust.setVisibility(View.GONE);