Composer: Show cancellable operations and errors inline.

'Send' and 'Save Draft' are now asynchronous and run outside of
Evolution's MailMsg infrastructure.

Add an EActivityBar to the composer window so these asynchronous
operations can be tracked and cancelled even in the absense of a main
window.  Also add an EAlertBar to the composer window so error messages
can be shown directly in the window.

Instead of calling e_alert_dialog_run_for_args(), call e_alert_submit()
and pass the EMsgComposer as the widget argument.  The EMsgComposer will
decide whether to show an EAlertDialog or use the EAlertBar, depending
on the GtkMessageType of the alert.

1 files changed, 846 insertions, 0 deletions

diff --git a/mail/e-mail-session-utils.c b/mail/e-mail-session-utils.c
new file mode 100644
index 0000000000..e9cdd83914
--- /dev/null
+++ b/mail/e-mail-session-utils.c
@@ -0,0 +1,846 @@
+/*
+ * e-mail-session-utils.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#include "e-mail-session-utils.h"
+
+#include <config.h>
+#include <glib/gi18n-lib.h>
+
+#include <mail/mail-tools.h>
+#include <mail/e-mail-local.h>
+#include <e-util/e-account-utils.h>
+#include <filter/e-filter-rule.h>
+
+/* X-Mailer header value */
+#define X_MAILER ("Evolution " VERSION SUB_VERSION " " VERSION_COMMENT)
+
+typedef struct _AsyncContext AsyncContext;
+
+struct _AsyncContext {
+	CamelFolder *sent_folder;
+	CamelFolder *outbox_folder;
+
+	CamelMimeMessage *message;
+	CamelMessageInfo *info;
+
+	CamelAddress *from;
+	CamelAddress *recipients;
+
+	CamelFilterDriver *driver;
+
+	GCancellable *cancellable;
+	gint io_priority;
+
+	/* X-Evolution headers */
+	struct _camel_header_raw *xev;
+
+	GPtrArray *post_to_uris;
+
+	gchar *destination;
+	gchar *message_uid;
+	gchar *transport_uri;
+	gchar *sent_folder_uri;
+};
+
+static void
+async_context_free (AsyncContext *context)
+{
+	if (context->sent_folder != NULL)
+		g_object_unref (context->sent_folder);
+
+	if (context->outbox_folder != NULL)
+		g_object_unref (context->outbox_folder);
+
+	if (context->message != NULL)
+		g_object_unref (context->message);
+
+	if (context->info != NULL)
+		camel_message_info_free (context->info);
+
+	if (context->from != NULL)
+		g_object_unref (context->from);
+
+	if (context->recipients != NULL)
+		g_object_unref (context->recipients);
+
+	if (context->driver != NULL)
+		g_object_unref (context->driver);
+
+	if (context->cancellable != NULL) {
+		camel_operation_pop_message (context->cancellable);
+		g_object_unref (context->cancellable);
+	}
+
+	if (context->xev != NULL)
+		camel_header_raw_clear (&context->xev);
+
+	if (context->post_to_uris != NULL) {
+		g_ptr_array_foreach (
+			context->post_to_uris, (GFunc) g_free, NULL);
+		g_ptr_array_free (context->post_to_uris, TRUE);
+	}
+
+	g_free (context->destination);
+	g_free (context->message_uid);
+	g_free (context->transport_uri);
+	g_free (context->sent_folder_uri);
+
+	g_slice_free (AsyncContext, context);
+}
+
+static void
+mail_session_handle_draft_headers_thread (GSimpleAsyncResult *simple,
+                                          EMailSession *session,
+                                          GCancellable *cancellable)
+{
+	AsyncContext *context;
+	GError *error = NULL;
+
+	context = g_simple_async_result_get_op_res_gpointer (simple);
+
+	e_mail_session_handle_draft_headers_sync (
+		session, context->message, cancellable, &error);
+
+	if (error != NULL) {
+		g_simple_async_result_set_from_error (simple, error);
+		g_error_free (error);
+	}
+}
+
+gboolean
+e_mail_session_handle_draft_headers_sync (EMailSession *session,
+                                          CamelMimeMessage *message,
+                                          GCancellable *cancellable,
+                                          GError **error)
+{
+	CamelFolder *folder;
+	CamelMedium *medium;
+	const gchar *folder_uri;
+	const gchar *message_uid;
+	const gchar *header_name;
+	gboolean success;
+
+	g_return_val_if_fail (E_IS_MAIL_SESSION (session), FALSE);
+	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (message), FALSE);
+
+	medium = CAMEL_MEDIUM (message);
+
+	header_name = "X-Evolution-Draft-Folder";
+	folder_uri = camel_medium_get_header (medium, header_name);
+
+	header_name = "X-Evolution-Draft-Message";
+	message_uid = camel_medium_get_header (medium, header_name);
+
+	/* Don't report errors about missing X-Evolution-Draft
+	 * headers.  These headers are optional, so their absence
+	 * is handled by doing nothing. */
+	if (folder_uri == NULL || message_uid == NULL)
+		return TRUE;
+
+	folder = e_mail_session_uri_to_folder_sync (
+		session, folder_uri, 0, cancellable, error);
+
+	if (folder == NULL)
+		return FALSE;
+
+	camel_folder_set_message_flags (
+		folder, message_uid,
+		CAMEL_MESSAGE_DELETED | CAMEL_MESSAGE_SEEN,
+		CAMEL_MESSAGE_DELETED | CAMEL_MESSAGE_SEEN);
+
+	success = camel_folder_synchronize_message_sync (
+		folder, message_uid, cancellable, error);
+
+	g_object_unref (folder);
+
+	return success;
+}
+
+void
+e_mail_session_handle_draft_headers (EMailSession *session,
+                                     CamelMimeMessage *message,
+                                     gint io_priority,
+                                     GCancellable *cancellable,
+                                     GAsyncReadyCallback callback,
+                                     gpointer user_data)
+{
+	GSimpleAsyncResult *simple;
+	AsyncContext *context;
+
+	g_return_if_fail (E_IS_MAIL_SESSION (session));
+	g_return_if_fail (CAMEL_IS_MIME_MESSAGE (message));
+
+	context = g_slice_new0 (AsyncContext);
+	context->message = g_object_ref (message);
+
+	simple = g_simple_async_result_new (
+		G_OBJECT (session), callback, user_data,
+		e_mail_session_handle_draft_headers);
+
+	g_simple_async_result_set_op_res_gpointer (
+		simple, context, (GDestroyNotify) async_context_free);
+
+	g_simple_async_result_run_in_thread (
+		simple, (GSimpleAsyncThreadFunc)
+		mail_session_handle_draft_headers_thread,
+		io_priority, cancellable);
+
+	g_object_unref (simple);
+}
+
+gboolean
+e_mail_session_handle_draft_headers_finish (EMailSession *session,
+                                            GAsyncResult *result,
+                                            GError **error)
+{
+	GSimpleAsyncResult *simple;
+
+	g_return_val_if_fail (
+		g_simple_async_result_is_valid (
+		result, G_OBJECT (session),
+		e_mail_session_handle_draft_headers), FALSE);
+
+	simple = G_SIMPLE_ASYNC_RESULT (result);
+
+	/* Assume success unless a GError is set. */
+	return !g_simple_async_result_propagate_error (simple, error);
+}
+
+static void
+mail_session_handle_source_headers_thread (GSimpleAsyncResult *simple,
+                                           EMailSession *session,
+                                           GCancellable *cancellable)
+{
+	AsyncContext *context;
+	GError *error = NULL;
+
+	context = g_simple_async_result_get_op_res_gpointer (simple);
+
+	e_mail_session_handle_source_headers_sync (
+		session, context->message, cancellable, &error);
+
+	if (error != NULL) {
+		g_simple_async_result_set_from_error (simple, error);
+		g_error_free (error);
+	}
+}
+
+gboolean
+e_mail_session_handle_source_headers_sync (EMailSession *session,
+                                           CamelMimeMessage *message,
+                                           GCancellable *cancellable,
+                                           GError **error)
+{
+	CamelFolder *folder;
+	CamelMedium *medium;
+	CamelMessageFlags flags = 0;
+	const gchar *folder_uri;
+	const gchar *message_uid;
+	const gchar *flag_string;
+	const gchar *header_name;
+	gboolean success;
+	guint length, ii;
+	gchar **tokens;
+	gchar *string;
+
+	g_return_val_if_fail (E_IS_MAIL_SESSION (session), FALSE);
+	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (message), FALSE);
+
+	medium = CAMEL_MEDIUM (message);
+
+	header_name = "X-Evolution-Source-Folder";
+	folder_uri = camel_medium_get_header (medium, header_name);
+
+	header_name = "X-Evolution-Source-Message";
+	message_uid = camel_medium_get_header (medium, header_name);
+
+	header_name = "X-Evolution-Source-Flags";
+	flag_string = camel_medium_get_header (medium, header_name);
+
+	/* Don't report errors about missing X-Evolution-Source
+	 * headers.  These headers are optional, so their absence
+	 * is handled by doing nothing. */
+	if (folder_uri == NULL || message_uid == NULL || flag_string == NULL)
+		return TRUE;
+
+	/* Convert the flag string to CamelMessageFlags. */
+
+	string = g_strstrip (g_strdup (flag_string));
+	tokens = g_strsplit (string, " ", 0);
+	g_free (string);
+
+	/* If tokens is NULL, a length of 0 will skip the loop. */
+	length = (tokens != NULL) ? g_strv_length (tokens) : 0;
+
+	for (ii = 0; ii < length; ii++) {
+		/* Note: We're only checking for flags known to
+		 * be used in X-Evolution-Source-Flags headers.
+		 * Add more as needed. */
+		if (g_strcmp0 (tokens[ii], "ANSWERED") == 0)
+			flags |= CAMEL_MESSAGE_ANSWERED;
+		else if (g_strcmp0 (tokens[ii], "ANSWERED_ALL") == 0)
+			flags |= CAMEL_MESSAGE_ANSWERED_ALL;
+		else if (g_strcmp0 (tokens[ii], "FORWARDED") == 0)
+			flags |= CAMEL_MESSAGE_FORWARDED;
+		else if (g_strcmp0 (tokens[ii], "SEEN") == 0)
+			flags |= CAMEL_MESSAGE_SEEN;
+		else
+			g_warning (
+				"Unknown flag '%s' in %s",
+				tokens[ii], header_name);
+	}
+
+	g_strfreev (tokens);
+
+	folder = e_mail_session_uri_to_folder_sync (
+		session, folder_uri, 0, cancellable, error);
+
+	if (folder == NULL)
+		return FALSE;
+
+	camel_folder_set_message_flags (
+		folder, message_uid, flags, flags);
+
+	success = camel_folder_synchronize_message_sync (
+		folder, message_uid, cancellable, error);
+
+	g_object_unref (folder);
+
+	return success;
+}
+
+void
+e_mail_session_handle_source_headers (EMailSession *session,
+                                      CamelMimeMessage *message,
+                                      gint io_priority,
+                                      GCancellable *cancellable,
+                                      GAsyncReadyCallback callback,
+                                      gpointer user_data)
+{
+	GSimpleAsyncResult *simple;
+	AsyncContext *context;
+
+	g_return_if_fail (E_IS_MAIL_SESSION (session));
+	g_return_if_fail (CAMEL_IS_MIME_MESSAGE (message));
+
+	context = g_slice_new0 (AsyncContext);
+	context->message = g_object_ref (message);
+
+	simple = g_simple_async_result_new (
+		G_OBJECT (session), callback, user_data,
+		e_mail_session_handle_source_headers);
+
+	g_simple_async_result_set_op_res_gpointer (
+		simple, context, (GDestroyNotify) async_context_free);
+
+	g_simple_async_result_run_in_thread (
+		simple, (GSimpleAsyncThreadFunc)
+		mail_session_handle_source_headers_thread,
+		io_priority, cancellable);
+
+	g_object_unref (simple);
+}
+
+gboolean
+e_mail_session_handle_source_headers_finish (EMailSession *session,
+                                             GAsyncResult *result,
+                                             GError **error)
+{
+	GSimpleAsyncResult *simple;
+
+	g_return_val_if_fail (
+		g_simple_async_result_is_valid (
+		result, G_OBJECT (session),
+		e_mail_session_handle_draft_headers), FALSE);
+
+	simple = G_SIMPLE_ASYNC_RESULT (result);
+
+	/* Assume success unless a GError is set. */
+	return !g_simple_async_result_propagate_error (simple, error);
+}
+
+static void
+mail_session_send_to_thread (GSimpleAsyncResult *simple,
+                             EMailSession *session,
+                             GCancellable *cancellable)
+{
+	AsyncContext *context;
+	CamelFolder *local_sent_folder;
+	GString *error_messages;
+	gboolean copy_to_sent = TRUE;
+	guint ii;
+	GError *error = NULL;
+
+	context = g_simple_async_result_get_op_res_gpointer (simple);
+
+	/* Send the message to all recipients. */
+	if (camel_address_length (context->recipients) > 0) {
+		CamelTransport *transport;
+		CamelProviderFlags flags;
+
+		/* XXX This API does not allow for cancellation. */
+		transport = camel_session_get_transport (
+			CAMEL_SESSION (session),
+			context->transport_uri, &error);
+
+		if (error != NULL) {
+			g_warn_if_fail (transport == NULL);
+			g_simple_async_result_set_from_error (simple, error);
+			g_error_free (error);
+			return;
+		}
+
+		g_return_if_fail (CAMEL_IS_TRANSPORT (transport));
+
+		flags = CAMEL_SERVICE (transport)->provider->flags;
+		if (flags & CAMEL_PROVIDER_DISABLE_SENT_FOLDER)
+			copy_to_sent = FALSE;
+
+		camel_transport_send_to_sync (
+			transport, context->message,
+			context->from, context->recipients,
+			cancellable, &error);
+
+		g_object_unref (transport);
+
+		if (error != NULL) {
+			g_simple_async_result_set_from_error (simple, error);
+			g_error_free (error);
+			return;
+		}
+	}
+
+	/* Post the message to requested folders. */
+	for (ii = 0; ii < context->post_to_uris->len; ii++) {
+		CamelFolder *folder;
+		const gchar *folder_uri;
+
+		folder_uri = g_ptr_array_index (context->post_to_uris, ii);
+
+		folder = e_mail_session_uri_to_folder_sync (
+			session, folder_uri, 0, cancellable, &error);
+
+		if (error != NULL) {
+			g_warn_if_fail (folder == NULL);
+			g_simple_async_result_set_from_error (simple, error);
+			g_error_free (error);
+			return;
+		}
+
+		g_return_if_fail (CAMEL_IS_FOLDER (folder));
+
+		camel_folder_append_message_sync (
+			folder, context->message, context->info,
+			NULL, cancellable, &error);
+
+		g_object_unref (folder);
+
+		if (error != NULL) {
+			g_simple_async_result_set_from_error (simple, error);
+			g_error_free (error);
+			return;
+		}
+	}
+
+	/*** Post Processing ***/
+
+	/* This accumulates error messages during post-processing. */
+	error_messages = g_string_sized_new (256);
+
+	mail_tool_restore_xevolution_headers (context->message, context->xev);
+
+	/* Run filters on the outgoing message. */
+	if (context->driver != NULL) {
+		camel_filter_driver_filter_message (
+			context->driver, context->message, context->info,
+			NULL, NULL, NULL, "", cancellable, &error);
+
+		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+			goto exit;
+
+		if (error != NULL) {
+			g_string_append_printf (
+				error_messages,
+				_("Failed to apply outgoing filters: %s"),
+				error->message);
+			g_clear_error (&error);
+		}
+	}
+
+	if (!copy_to_sent)
+		goto cleanup;
+
+	/* Append the sent message to a Sent folder. */
+
+	local_sent_folder = e_mail_local_get_folder (E_MAIL_FOLDER_SENT);
+
+	/* Try to extract a CamelFolder from the Sent folder URI. */
+	if (context->sent_folder_uri != NULL) {
+		context->sent_folder = e_mail_session_uri_to_folder_sync (
+			session, context->sent_folder_uri, 0,
+			cancellable, &error);
+		if (error != NULL) {
+			g_warn_if_fail (context->sent_folder == NULL);
+			if (error_messages->len > 0)
+				g_string_append (error_messages, "\n\n");
+			g_string_append_printf (
+				error_messages,
+				_("Failed to append to %s: %s\n"
+				  "Appending to local 'Sent' folder instead."),
+				context->sent_folder_uri, error->message);
+			g_clear_error (&error);
+		}
+	}
+
+	/* Fall back to the local Sent folder. */
+	if (context->sent_folder == NULL)
+		context->sent_folder = g_object_ref (local_sent_folder);
+
+	/* Append the message. */
+	camel_folder_append_message_sync (
+		context->sent_folder, context->message,
+		context->info, NULL, cancellable, &error);
+
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+		goto exit;
+
+	if (error == NULL)
+		goto cleanup;
+
+	/* If appending to a remote Sent folder failed,
+	 * try appending to the local Sent folder. */
+	if (context->sent_folder != local_sent_folder) {
+		const gchar *description;
+
+		description = camel_folder_get_description (
+			context->sent_folder);
+
+		if (error_messages->len > 0)
+			g_string_append (error_messages, "\n\n");
+		g_string_append_printf (
+			error_messages,
+			_("Failed to append to %s: %s\n"
+			  "Appending to local 'Sent' folder instead."),
+			description, error->message);
+		g_clear_error (&error);
+
+		camel_folder_append_message_sync (
+			local_sent_folder, context->message,
+			context->info, NULL, cancellable, &error);
+	}
+
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+		goto exit;
+
+	/* We can't even append to the local Sent folder?
+	 * In that case just leave the message in Outbox. */
+	if (error != NULL) {
+		if (error_messages->len > 0)
+			g_string_append (error_messages, "\n\n");
+		g_string_append_printf (
+			error_messages,
+			_("Failed to append to local 'Sent' folder: %s"),
+			error->message);
+		g_clear_error (&error);
+		goto exit;
+	}
+
+cleanup:
+
+	/* The send operation was successful; ignore cleanup errors. */
+
+	/* Mark the Outbox message for deletion. */
+	camel_folder_set_message_flags (
+		context->outbox_folder, context->message_uid,
+		CAMEL_MESSAGE_DELETED | CAMEL_MESSAGE_SEEN, ~0);
+
+	/* Synchronize the Outbox folder. */
+	camel_folder_synchronize_sync (
+		context->outbox_folder, FALSE, cancellable, &error);
+	if (error != NULL) {
+		g_warning ("%s", error->message);
+		g_clear_error (&error);
+	}
+
+	/* Mark the draft message for deletion, if present. */
+	e_mail_session_handle_draft_headers_sync (
+		session, context->message, cancellable, &error);
+	if (error != NULL) {
+		g_warning ("%s", error->message);
+		g_clear_error (&error);
+	}
+
+	/* Set flags on the original source message, if present.
+	 * Source message refers to the message being forwarded
+	 * or replied to. */
+	e_mail_session_handle_source_headers_sync (
+		session, context->message, cancellable, &error);
+	if (error != NULL) {
+		g_warning ("%s", error->message);
+		g_clear_error (&error);
+	}
+
+exit:
+
+	/* If we were cancelled, disregard any other errors. */
+	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED)) {
+		g_simple_async_result_set_from_error (simple, error);
+		g_error_free (error);
+
+	/* Stuff the accumulated error messages in a GError. */
+	} else if (error_messages->len > 0) {
+		g_simple_async_result_set_error (
+			simple, CAMEL_ERROR, CAMEL_ERROR_GENERIC,
+			"%s", error_messages->str);
+	}
+
+	/* Synchronize the Sent folder. */
+	if (context->sent_folder != NULL)
+		camel_folder_synchronize_sync (
+			context->sent_folder, FALSE, cancellable, NULL);
+
+	g_string_free (error_messages, TRUE);
+}
+
+static void
+mail_session_send_to_prepare (CamelFolder *outbox_folder,
+                              GAsyncResult *result,
+                              GSimpleAsyncResult *simple)
+{
+	AsyncContext *context;
+	CamelAddress *from;
+	CamelAddress *recipients;
+	CamelMedium *medium;
+	CamelMessageInfo *info;
+	CamelMimeMessage *message;
+	EAccount *account = NULL;
+	GPtrArray *post_to_uris;
+	struct _camel_header_raw *xev;
+	struct _camel_header_raw *header;
+	const gchar *string;
+	const gchar *resent_from;
+	gchar *transport_uri = NULL;
+	gchar *sent_folder_uri = NULL;
+	GError *error = NULL;
+
+	context = g_simple_async_result_get_op_res_gpointer (simple);
+
+	message = camel_folder_get_message_finish (
+		outbox_folder, result, &error);
+
+	if (error != NULL) {
+		g_warn_if_fail (message == NULL);
+		g_simple_async_result_set_from_error (simple, error);
+		g_simple_async_result_complete (simple);
+		g_object_unref (simple);
+		g_error_free (error);
+		return;
+	}
+
+	g_return_if_fail (CAMEL_IS_MIME_MESSAGE (message));
+
+	medium = CAMEL_MEDIUM (message);
+
+	camel_medium_set_header (medium, "X-Mailer", X_MAILER);
+
+	xev = mail_tool_remove_xevolution_headers (message);
+
+	/* Extract directives from X-Evolution headers. */
+
+	string = camel_header_raw_find (&xev, "X-Evolution-Account", NULL);
+	if (string != NULL) {
+		gchar *account_uid;
+
+		account_uid = g_strstrip (g_strdup (string));
+		account = e_get_account_by_uid (account_uid);
+		g_free (account_uid);
+	}
+
+	if (account != NULL) {
+		if (account->transport != NULL)
+			transport_uri = g_strdup (account->transport->url);
+		sent_folder_uri = g_strdup (account->sent_folder_uri);
+	}
+
+	string = camel_header_raw_find (&xev, "X-Evolution-Transport", NULL);
+	if (transport_uri == NULL && string != NULL)
+		transport_uri = g_strstrip (g_strdup (string));
+
+	string = camel_header_raw_find (&xev, "X-Evolution-Fcc", NULL);
+	if (sent_folder_uri == NULL && string != NULL)
+		sent_folder_uri = g_strstrip (g_strdup (string));
+
+	if (transport_uri == NULL)
+		transport_uri = g_strdup (context->destination);
+
+	post_to_uris = g_ptr_array_new ();
+	for (header = xev; header != NULL; header = header->next) {
+		gchar *folder_uri;
+
+		if (g_strcmp0 (header->name, "X-Evolution-PostTo") != 0)
+			continue;
+
+		folder_uri = g_strstrip (g_strdup (header->name));
+		g_ptr_array_add (post_to_uris, folder_uri);
+	}
+
+	/* Collect sender and recipients from headers. */
+
+	from = (CamelAddress *) camel_internet_address_new ();
+	recipients = (CamelAddress *) camel_internet_address_new ();
+	resent_from = camel_medium_get_header (medium, "Resent-From");
+
+	if (resent_from != NULL) {
+		const CamelInternetAddress *addr;
+		const gchar *type;
+
+		camel_address_decode (from, resent_from);
+
+		type = CAMEL_RECIPIENT_TYPE_RESENT_TO;
+		addr = camel_mime_message_get_recipients (message, type);
+		camel_address_cat (recipients, CAMEL_ADDRESS (addr));
+
+		type = CAMEL_RECIPIENT_TYPE_RESENT_CC;
+		addr = camel_mime_message_get_recipients (message, type);
+		camel_address_cat (recipients, CAMEL_ADDRESS (addr));
+
+		type = CAMEL_RECIPIENT_TYPE_RESENT_BCC;
+		addr = camel_mime_message_get_recipients (message, type);
+		camel_address_cat (recipients, CAMEL_ADDRESS (addr));
+
+	} else {
+		const CamelInternetAddress *addr;
+		const gchar *type;
+
+		addr = camel_mime_message_get_from (message);
+		camel_address_copy (from, CAMEL_ADDRESS (addr));
+
+		type = CAMEL_RECIPIENT_TYPE_TO;
+		addr = camel_mime_message_get_recipients (message, type);
+		camel_address_cat (recipients, CAMEL_ADDRESS (addr));
+
+		type = CAMEL_RECIPIENT_TYPE_CC;
+		addr = camel_mime_message_get_recipients (message, type);
+		camel_address_cat (recipients, CAMEL_ADDRESS (addr));
+
+		type = CAMEL_RECIPIENT_TYPE_BCC;
+		addr = camel_mime_message_get_recipients (message, type);
+		camel_address_cat (recipients, CAMEL_ADDRESS (addr));
+	}
+
+	/* Miscellaneous preparations. */
+
+	info = camel_message_info_new (NULL);
+	camel_message_info_set_flags (info, CAMEL_MESSAGE_SEEN, ~0);
+
+	/* The rest of the processing happens in a thread. */
+
+	context->from = from;
+	context->recipients = recipients;
+	context->message = g_object_ref (message);
+	context->info = info;
+	context->xev = xev;
+	context->post_to_uris = post_to_uris;
+	context->transport_uri = transport_uri;
+	context->sent_folder_uri = sent_folder_uri;
+
+	g_simple_async_result_run_in_thread (
+		simple, (GSimpleAsyncThreadFunc)
+		mail_session_send_to_thread,
+		context->io_priority,
+		context->cancellable);
+
+	g_object_unref (simple);
+}
+
+void
+e_mail_session_send_to (EMailSession *session,
+                        CamelFolder *outbox_folder,
+                        const gchar *message_uid,
+                        const gchar *destination,
+                        gint io_priority,
+                        GCancellable *cancellable,
+                        CamelFilterGetFolderFunc get_folder_func,
+                        gpointer get_folder_data,
+                        GAsyncReadyCallback callback,
+                        gpointer user_data)
+{
+	GSimpleAsyncResult *simple;
+	AsyncContext *context;
+	GError *error = NULL;
+
+	g_return_if_fail (E_IS_MAIL_SESSION (session));
+	g_return_if_fail (CAMEL_IS_FOLDER (outbox_folder));
+	g_return_if_fail (message_uid != NULL);
+
+	context = g_slice_new0 (AsyncContext);
+	context->outbox_folder = g_object_ref (outbox_folder);
+	context->message_uid = g_strdup (message_uid);
+	context->destination = g_strdup (destination);
+	context->io_priority = io_priority;
+
+	if (G_IS_CANCELLABLE (cancellable))
+		context->cancellable = g_object_ref (cancellable);
+
+	/* More convenient to do this here than in the prepare function.
+	 * Failure here emits a runtime warning but is non-fatal. */
+	context->driver = camel_session_get_filter_driver (
+		CAMEL_SESSION (session), E_FILTER_SOURCE_OUTGOING, &error);
+	if (context->driver != NULL)
+		camel_filter_driver_set_folder_func (
+			context->driver, get_folder_func, get_folder_data);
+	if (error != NULL) {
+		g_warn_if_fail (context->driver == NULL);
+		g_warning ("%s", error->message);
+		g_error_free (error);
+	}
+
+	simple = g_simple_async_result_new (
+		G_OBJECT (session), callback,
+		user_data, e_mail_session_send_to);
+
+	g_simple_async_result_set_op_res_gpointer (
+		simple, context, (GDestroyNotify) async_context_free);
+
+	/* This gets popped in async_context_free(). */
+	camel_operation_push_message (
+		context->cancellable, _("Sending message"));
+
+	camel_folder_get_message (
+		outbox_folder, message_uid, io_priority,
+		context->cancellable, (GAsyncReadyCallback)
+		mail_session_send_to_prepare, simple);
+}
+
+gboolean
+e_mail_session_send_to_finish (EMailSession *session,
+                               GAsyncResult *result,
+                               GError **error)
+{
+	GSimpleAsyncResult *simple;
+
+	g_return_val_if_fail (
+		g_simple_async_result_is_valid (
+		result, G_OBJECT (session),
+		e_mail_session_send_to), FALSE);
+
+	simple = G_SIMPLE_ASYNC_RESULT (result);
+
+	/* Assume success unless a GError is set. */
+	return !g_simple_async_result_propagate_error (simple, error);
+}