feat: do not resolve MX records during configuration

MX record lookup was only used to detect Google Workspace domains.
They can still be configured manually.
We anyway do not want to encourage creating new profiles
with Google Workspace as we don't have Gmail OAUTH2 token anymore
and new users can more easily onboard with a chatmail relay.

Author: link2xt

Cargo.lock

@@ -61,7 +61,6 @@ fd-lock = "4"
 futures-lite = { workspace = true }
 futures = { workspace = true }
 hex = "0.4.0"
-hickory-resolver = "0.25.2"
 http-body-util = "0.1.3"
 humansize = "2"
 hyper = "1"

Cargo.toml

@@ -5350,18 +5350,17 @@ dc_provider_t*  dc_provider_new_from_email            (const dc_context_t* conte
 
 
 /**
- * Create a provider struct for the given e-mail address by local and DNS lookup.
+ * Create a provider struct for the given e-mail address by local lookup.
  *
- * First lookup is done from the local database as of dc_provider_new_from_email().
- * If the first lookup fails, an additional DNS lookup is done,
- * trying to figure out the provider belonging to custom domains.
+ * DNS lookup is not used anymore and this function is deprecated.
  *
  * @memberof dc_provider_t
  * @param context The context object.
  * @param email The user's e-mail address to extract the provider info form.
  * @return A dc_provider_t struct which can be used with the dc_provider_get_*
  *     accessor functions. If no provider info is found, NULL will be
  *     returned.
+ * @deprecated 2025-10-17 use dc_provider_new_from_email() instead.
  */
 dc_provider_t*  dc_provider_new_from_email_with_dns    (const dc_context_t* context, const char* email);
 

deltachat-ffi/deltachat.h

@@ -4661,13 +4661,9 @@ pub unsafe extern "C" fn dc_provider_new_from_email(
 
     let ctx = &*context;
 
-    match block_on(provider::get_provider_info_by_addr(
-        ctx,
-        addr.as_str(),
-        true,
-    ))
-    .log_err(ctx)
-    .unwrap_or_default()
+    match provider::get_provider_info_by_addr(addr.as_str())
+        .log_err(ctx)
+        .unwrap_or_default()
     {
         Some(provider) => provider,
         None => ptr::null_mut(),
@@ -4686,25 +4682,13 @@ pub unsafe extern "C" fn dc_provider_new_from_email_with_dns(
     let addr = to_string_lossy(addr);
 
     let ctx = &*context;
-    let proxy_enabled = block_on(ctx.get_config_bool(config::Config::ProxyEnabled))
-        .context("Can't get config")
-        .log_err(ctx);
 
-    match proxy_enabled {
-        Ok(proxy_enabled) => {
-            match block_on(provider::get_provider_info_by_addr(
-                ctx,
-                addr.as_str(),
-                proxy_enabled,
-            ))
-            .log_err(ctx)
-            .unwrap_or_default()
-            {
-                Some(provider) => provider,
-                None => ptr::null_mut(),
-            }
-        }
-        Err(_) => ptr::null_mut(),
+    match provider::get_provider_info_by_addr(addr.as_str())
+        .log_err(ctx)
+        .unwrap_or_default()
+    {
+        Some(provider) => provider,
+        None => ptr::null_mut(),
     }
 }
 

deltachat-ffi/src/lib.rs

@@ -336,21 +336,10 @@ impl CommandApi {
     /// instead of the domain.
     async fn get_provider_info(
         &self,
-        account_id: u32,
+        _account_id: u32,
         email: String,
     ) -> Result<Option<ProviderInfo>> {
-        let ctx = self.get_context(account_id).await?;
-
-        let proxy_enabled = ctx
-            .get_config_bool(deltachat::config::Config::ProxyEnabled)
-            .await?;
-
-        let provider_info = get_provider_info(
-            &ctx,
-            email.split('@').next_back().unwrap_or(""),
-            proxy_enabled,
-        )
-        .await;
+        let provider_info = get_provider_info(email.split('@').next_back().unwrap_or(""));
         Ok(ProviderInfo::from_dc_type(provider_info))
     }
 

deltachat-jsonrpc/src/api.rs

@@ -1266,10 +1266,7 @@ pub async fn cmdline(context: Context, line: &str, chat_id: &mut ChatId) -> Resu
         }
         "providerinfo" => {
             ensure!(!arg1.is_empty(), "Argument <addr> missing.");
-            let proxy_enabled = context
-                .get_config_bool(config::Config::ProxyEnabled)
-                .await?;
-            match provider::get_provider_info(&context, arg1, proxy_enabled).await {
+            match provider::get_provider_info(arg1) {
                 Some(info) => {
                     println!("Information for provider belonging to {arg1}:");
                     println!("status: {}", info.status as u32);

deltachat-repl/src/cmdline.rs

@@ -570,8 +570,11 @@ def test_provider_info(rpc) -> None:
     assert provider_info is None
 
     # Test MX record resolution.
+    # This previously resulted in Gmail provider
+    # because MX record pointed to google.com domain,
+    # but MX record resolution has been removed.
     provider_info = rpc.get_provider_info(account_id, "github.com")
-    assert provider_info["id"] == "gmail"
+    assert provider_info is None
 
     # Disable MX record resolution.
     rpc.set_config(account_id, "proxy_enabled", "1")

deltachat-rpc-client/tests/test_something.py

@@ -300,8 +300,6 @@ async fn get_configured_param(
         param.smtp.password.clone()
     };
 
-    let proxy_enabled = ctx.get_config_bool(Config::ProxyEnabled).await?;
-
     let mut addr = param.addr.clone();
     if param.oauth2 {
         // the used oauth2 addr may differ, check this.
@@ -343,7 +341,7 @@ async fn get_configured_param(
             "checking internal provider-info for offline autoconfig"
         );
 
-        provider = provider::get_provider_info(ctx, &param_domain, proxy_enabled).await;
+        provider = provider::get_provider_info(&param_domain);
         if let Some(provider) = provider {
             if provider.server.is_empty() {
                 info!(ctx, "Offline autoconfig found, but no servers defined.");

src/configure.rs

@@ -53,7 +53,7 @@ pub async fn get_oauth2_url(
     addr: &str,
     redirect_uri: &str,
 ) -> Result<Option<String>> {
-    if let Some(oauth2) = Oauth2::from_address(context, addr).await {
+    if let Some(oauth2) = Oauth2::from_address(addr) {
         context
             .sql
             .set_raw_config("oauth2_pending_redirect_uri", Some(redirect_uri))
@@ -73,7 +73,7 @@ pub(crate) async fn get_oauth2_access_token(
     code: &str,
     regenerate: bool,
 ) -> Result<Option<String>> {
-    if let Some(oauth2) = Oauth2::from_address(context, addr).await {
+    if let Some(oauth2) = Oauth2::from_address(addr) {
         let lock = context.oauth2_mutex.lock().await;
 
         // read generated token
@@ -221,7 +221,7 @@ pub(crate) async fn get_oauth2_addr(
     addr: &str,
     code: &str,
 ) -> Result<Option<String>> {
-    let oauth2 = match Oauth2::from_address(context, addr).await {
+    let oauth2 = match Oauth2::from_address(addr) {
         Some(o) => o,
         None => return Ok(None),
     };
@@ -256,15 +256,13 @@ pub(crate) async fn get_oauth2_addr(
 }
 
 impl Oauth2 {
-    async fn from_address(context: &Context, addr: &str) -> Option<Self> {
+    fn from_address(addr: &str) -> Option<Self> {
         let addr_normalized = normalize_addr(addr);
-        let skip_mx = true;
         if let Some(domain) = addr_normalized
             .find('@')
             .map(|index| addr_normalized.split_at(index + 1).1)
         {
-            if let Some(oauth2_authorizer) = provider::get_provider_info(context, domain, skip_mx)
-                .await
+            if let Some(oauth2_authorizer) = provider::get_provider_info(domain)
                 .and_then(|provider| provider.oauth2_authorizer.as_ref())
             {
                 return Some(match oauth2_authorizer {
@@ -354,21 +352,16 @@ mod tests {
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_oauth_from_address() {
-        let t = TestContext::new().await;
-
         // Delta Chat does not have working Gmail client ID anymore.
-        assert_eq!(Oauth2::from_address(&t, "hello@gmail.com").await, None);
-        assert_eq!(Oauth2::from_address(&t, "hello@googlemail.com").await, None);
+        assert_eq!(Oauth2::from_address("hello@gmail.com"), None);
+        assert_eq!(Oauth2::from_address("hello@googlemail.com"), None);
 
         assert_eq!(
-            Oauth2::from_address(&t, "hello@yandex.com").await,
-            Some(OAUTH2_YANDEX)
-        );
-        assert_eq!(
-            Oauth2::from_address(&t, "hello@yandex.ru").await,
+            Oauth2::from_address("hello@yandex.com"),
             Some(OAUTH2_YANDEX)
         );
-        assert_eq!(Oauth2::from_address(&t, "hello@web.de").await, None);
+        assert_eq!(Oauth2::from_address("hello@yandex.ru"), Some(OAUTH2_YANDEX));
+        assert_eq!(Oauth2::from_address("hello@web.de"), None);
     }
 
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]