diff --git a/deltachat-jsonrpc/src/api.rs b/deltachat-jsonrpc/src/api.rs
index f48c949c1..bdab3bba6 100644
--- a/deltachat-jsonrpc/src/api.rs
+++ b/deltachat-jsonrpc/src/api.rs
@@ -489,7 +489,7 @@ impl CommandApi {
         param: EnteredLoginParam,
     ) -> Result<()> {
         let ctx = self.get_context(account_id).await?;
-        ctx.add_or_update_transport(&param.try_into()?).await
+        ctx.add_or_update_transport(&mut param.try_into()?).await
     }
 
     /// Deprecated 2025-04. Alias for [Self::add_or_update_transport()].
diff --git a/deltachat-rpc-client/src/deltachat_rpc_client/account.py b/deltachat-rpc-client/src/deltachat_rpc_client/account.py
index 1b9f67e12..407e49a2a 100644
--- a/deltachat-rpc-client/src/deltachat_rpc_client/account.py
+++ b/deltachat-rpc-client/src/deltachat_rpc_client/account.py
@@ -115,6 +115,12 @@ class Account:
         """Add a new transport."""
         yield self._rpc.add_or_update_transport.future(self.id, params)
 
+    @futuremethod
+    def list_transports(self):
+        """Returns the list of all email accounts that are used as a transport in the current profile."""
+        transports = yield self._rpc.list_transports.future(self.id)
+        return transports
+
     def bring_online(self):
         """Start I/O and wait until IMAP becomes IDLE."""
         self.start_io()
diff --git a/deltachat-rpc-client/tests/test_something.py b/deltachat-rpc-client/tests/test_something.py
index 2c0b50868..d859140f7 100644
--- a/deltachat-rpc-client/tests/test_something.py
+++ b/deltachat-rpc-client/tests/test_something.py
@@ -74,6 +74,29 @@ def test_configure_starttls(acfactory) -> None:
     assert account.is_configured()
 
 
+def test_lowercase_address(acfactory) -> None:
+    addr, password = acfactory.get_credentials()
+    addr_upper = addr.upper()
+    account = acfactory.get_unconfigured_account()
+    account.add_or_update_transport(
+        {
+            "addr": addr_upper,
+            "password": password,
+        },
+    )
+    assert account.is_configured()
+    assert addr_upper != addr
+    assert account.get_config("configured_addr") == addr
+    assert account.list_transports()[0]["addr"] == addr
+
+    for param in [
+        account.get_info()["used_account_settings"],
+        account.get_info()["entered_account_settings"],
+    ]:
+        assert addr in param
+        assert addr_upper not in param
+
+
 def test_configure_ip(acfactory) -> None:
     addr, password = acfactory.get_credentials()
     account = acfactory.get_unconfigured_account()
@@ -115,7 +138,7 @@ def test_list_transports(acfactory) -> None:
             "imapUser": addr,
         },
     )
-    transports = account._rpc.list_transports(account.id)
+    transports = account.list_transports()
     assert len(transports) == 1
     params = transports[0]
     assert params["addr"] == addr
diff --git a/src/configure.rs b/src/configure.rs
index e0a63c7db..c3fe0afcd 100644
--- a/src/configure.rs
+++ b/src/configure.rs
@@ -16,7 +16,7 @@ pub(crate) mod server_params;
 use anyhow::{bail, ensure, format_err, Context as _, Result};
 use auto_mozilla::moz_autoconfigure;
 use auto_outlook::outlk_autodiscover;
-use deltachat_contact_tools::EmailAddress;
+use deltachat_contact_tools::{addr_normalize, EmailAddress};
 use futures::FutureExt;
 use futures_lite::FutureExt as _;
 use percent_encoding::utf8_percent_encode;
@@ -70,9 +70,9 @@ impl Context {
     /// Deprecated since 2025-02; use `add_transport_from_qr()`
     /// or `add_or_update_transport()` instead.
     pub async fn configure(&self) -> Result<()> {
-        let param = EnteredLoginParam::load(self).await?;
+        let mut param = EnteredLoginParam::load(self).await?;
 
-        self.add_transport_inner(&param).await
+        self.add_transport_inner(&mut param).await
     }
 
     /// Configures a new email account using the provided parameters
@@ -104,7 +104,7 @@ impl Context {
     ///   from a server encoded in a QR code.
     /// - [Self::list_transports()] to get a list of all configured transports.
     /// - [Self::delete_transport()] to remove a transport.
-    pub async fn add_or_update_transport(&self, param: &EnteredLoginParam) -> Result<()> {
+    pub async fn add_or_update_transport(&self, param: &mut EnteredLoginParam) -> Result<()> {
         self.stop_io().await;
         let result = self.add_transport_inner(param).await;
         if result.is_err() {
@@ -117,7 +117,7 @@ impl Context {
         Ok(())
     }
 
-    async fn add_transport_inner(&self, param: &EnteredLoginParam) -> Result<()> {
+    async fn add_transport_inner(&self, param: &mut EnteredLoginParam) -> Result<()> {
         ensure!(
             !self.scheduler.is_running().await,
             "cannot configure, already running"
@@ -126,6 +126,7 @@ impl Context {
             self.sql.is_open().await,
             "cannot configure, database not opened."
         );
+        param.addr = addr_normalize(&param.addr);
         let old_addr = self.get_config(Config::ConfiguredAddr).await?;
         if self.is_configured().await? && !addr_cmp(&old_addr.unwrap_or_default(), &param.addr) {
             bail!("Changing your email address is not supported right now. Check back in a few months!");