Initial commit of MIME/Mail functionality

14 files changed, 646 insertions, 7 deletions

diff --git a/icetray/icetray/Jamfile.jam b/icetray/icetray/Jamfile.jam
index bacda4e..09cf1b2 100644
--- a/icetray/icetray/Jamfile.jam
+++ b/icetray/icetray/Jamfile.jam
@@ -1,15 +1,22 @@
 import package ;
 
 lib boost_program_options ;
+lib esmtp ;
 
-obj logWriter : logWriter.ice :
-	<slicer>no
-	<include>.
-	<toolset>tidy:<checker>none
-	;
+rule iceobj ( name : source )
+{
+	obj $(name) : $(source) :
+		<slicer>no
+		<include>.
+		<toolset>tidy:<checker>none
+		;
+}
+iceobj logWriter : logWriter.ice ;
+iceobj mime : mime.ice ;
+iceobj mail : mail.ice ;
 lib icetray :
-	[ glob *.cpp *.ice ]
-	logWriter
+	[ glob *.cpp *.ice : mime.ice mail.ice ]
+	logWriter mime mail
 	:
 	<library>..//adhocutil
 	<library>..//dbppcore
@@ -20,6 +27,7 @@ lib icetray :
 	<library>..//slicer-db
 	<library>../..//glibmm
 	<library>boost_program_options
+	<library>esmtp
 	<implicit-dependency>logWriter
 	<slicer>pure
 	<include>.
diff --git a/icetray/icetray/mail.ice b/icetray/icetray/mail.ice
new file mode 100644
index 0000000..7f8bda4
--- /dev/null
+++ b/icetray/icetray/mail.ice
@@ -0,0 +1,33 @@
+#ifndef ICETRAY_MAIL
+#define ICETRAY_MAIL
+
+#include <mime.ice>
+
+[["ice-prefix"]]
+module IceTray {
+	module Mail {
+		local struct Address {
+			string name;
+			string address;
+		};
+
+		local class Email {
+			Address to;
+			Address from;
+			string subject;
+			Mime::BasicPart content;
+		};
+
+		["cpp:ice_print"]
+		local exception SendEmailFailed {
+			string message;
+		};
+
+		local interface MailServer {
+			idempotent void sendEmail(Email msg) throws SendEmailFailed;
+		};
+	};
+};
+
+#endif
+
diff --git a/icetray/icetray/mailServer.cpp b/icetray/icetray/mailServer.cpp
new file mode 100644
index 0000000..67287c8
--- /dev/null
+++ b/icetray/icetray/mailServer.cpp
@@ -0,0 +1,53 @@
+#include "mailServer.h"
+#include <libesmtp.h>
+#include <Ice/ObjectAdapter.h>
+#include <Ice/Communicator.h>
+#include <memstream.h>
+
+namespace IceTray {
+	namespace Mail {
+		LibesmtpMailServer::LibesmtpMailServer(std::string s) :
+			server(std::move(s))
+		{
+		}
+
+		void
+		LibesmtpMailServer::sendEmail(const EmailPtr & msg)
+		{
+			smtp_session_t session = smtp_create_session();
+			smtp_message_t message = smtp_add_message(session);
+			smtp_set_server(session, server.c_str());
+			smtp_set_header(message, "To", msg->to.name.c_str(), msg->to.address.c_str());
+			smtp_set_header(message, "From", msg->from.name.c_str(), msg->from.address.c_str());
+			smtp_set_header(message, "Subject", msg->subject.c_str());
+			smtp_add_recipient(message, msg->to.address.c_str());
+			AdHoc::MemStream ms;
+			writeEmailContent(msg, ms);
+			smtp_set_message_fp(message, ms);
+			if (!smtp_start_session(session)) {
+				char buf[BUFSIZ];
+				auto b = smtp_strerror(smtp_errno(), buf, sizeof(buf));
+				assert(b);
+				SendEmailFailed e(__FILE__, __LINE__, b);
+				smtp_destroy_session(session);
+				throw e;
+			}
+			smtp_destroy_session(session);
+		}
+
+		void
+		BasicMailServer::writeEmailContent(EmailPtr msg, FILE * ms)
+		{
+			fputs("MIME-Version: 1.0\r\n", ms);
+			msg->content->write({ ms }, 0);
+		}
+
+
+		void
+		SendEmailFailed::ice_print(std::ostream & buf) const
+		{
+			buf << "Failed to send email: " << message;
+		}
+	}
+}
+
diff --git a/icetray/icetray/mailServer.h b/icetray/icetray/mailServer.h
new file mode 100644
index 0000000..8f19877
--- /dev/null
+++ b/icetray/icetray/mailServer.h
@@ -0,0 +1,28 @@
+
+#ifndef ICETRAY_MAILSERVER_H
+#define ICETRAY_MAILSERVER_H
+
+#include <mail.h>
+#include <visibility.h>
+
+namespace IceTray {
+	namespace Mail {
+		class DLL_PUBLIC BasicMailServer {
+			public:
+				static void writeEmailContent(EmailPtr msg, FILE * ms);
+		};
+
+		class DLL_PUBLIC LibesmtpMailServer : public MailServer, BasicMailServer {
+			public:
+				LibesmtpMailServer(std::string server);
+
+				void sendEmail(const EmailPtr & msg) override;
+
+			private:
+				const std::string server;
+		};
+	}
+}
+
+#endif
+
diff --git a/icetray/icetray/mime.ice b/icetray/icetray/mime.ice
new file mode 100644
index 0000000..112b165
--- /dev/null
+++ b/icetray/icetray/mime.ice
@@ -0,0 +1,32 @@
+#ifndef ICETRAY_MIME
+#define ICETRAY_MIME
+
+[["ice-prefix"]]
+[["cpp:include:stream_support.h"]]
+module IceTray {
+	module Mime {
+		local dictionary<string, string> Headers;
+
+		local interface Writable {
+			["cpp:const"] void write(["cpp:type:StreamPtr"] string buffer, int depth);
+		};
+
+		local class BasicPart implements Writable {
+			Headers headers;
+		};
+
+		local sequence<BasicPart> Parts;
+
+		local class BasicSinglePart extends BasicPart {
+			string mimetype;
+		};
+
+		local class BasicMultiPart extends BasicPart {
+			string subtype;
+			Parts parts;
+		};
+	};
+};
+
+#endif
+
diff --git a/icetray/icetray/mimeImpl.cpp b/icetray/icetray/mimeImpl.cpp
new file mode 100644
index 0000000..74dfad5
--- /dev/null
+++ b/icetray/icetray/mimeImpl.cpp
@@ -0,0 +1,163 @@
+#include "mimeImpl.h"
+
+namespace IceTray::Mime {
+	static const char * const DIVIDER = "//divider//";
+	static const char mime_base64[] =
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+
+	void
+	PartHelper::writeHeaders(const Headers & headers, const StreamPtr & ms)
+	{
+		for (const auto & h : headers) {
+			if (h.second.empty()) {
+				continue;
+			}
+			fprintf(ms, "%s: %s\r\n", h.first.c_str(), h.second.c_str());
+		}
+	}
+
+	TextPart::TextPart(const Headers & h, const std::string & m, const std::string & p) :
+		BasicSinglePart(h, m),
+		payload(p)
+	{
+	}
+
+	void
+	TextPart::write(const StreamPtr & ms, Ice::Int) const
+	{
+		writeHeaders(headers, ms);
+		fputs("Content-Transfer-Encoding: quoted-printable\r\n", ms);
+		fprintf(ms, "Content-Type: %s; charset=\"utf-8\"\r\n\r\n",
+				mimetype.c_str());
+		quotedPrintable(payload, ms);
+		fputs("\r\n", ms);
+	}
+
+	void
+	TextPart::quotedPrintable(const std::string_view & input, FILE * ms, const size_t maxWidth)
+	{
+		size_t line = 0;
+		auto wrap = [&]() {
+			fputs("=\r\n", ms);
+			line = 0;
+		};
+		auto wrapIfNeeded = [&](size_t need) {
+			if (line + need > maxWidth) {
+				wrap();
+			}
+		};
+		for (const auto & ch : input) {
+			const auto & nextCh = *(&ch + 1);
+			if (ch == '\r') {
+			}
+			else if (ch == '\n') {
+				fputs("\r\n", ms);
+				line = 0;
+			}
+			else if (ch == ' ' || ch == '\t') {
+				if (nextCh == '\r' || nextCh == '\n') {
+					wrapIfNeeded(3);
+					fprintf(ms, "=%02X", (uint8_t)ch);
+					line += 3;
+				}
+				else {
+					wrapIfNeeded(1);
+					fputc(ch, ms);
+					line += 1;
+				}
+			}
+			else if ((ch >= 33 && ch < 61) || (ch > 61 && ch <= 126)) {
+				wrapIfNeeded(1);
+				fputc(ch, ms);
+				line += 1;
+			}
+			else {
+				wrapIfNeeded(3);
+				fprintf(ms, "=%02X", (uint8_t)ch);
+				line += 3;
+			}
+		}
+	}
+
+	BinaryViewPart::BinaryViewPart(const Headers & h, const std::string & m, const std::basic_string_view<uint8_t> & v) :
+		BasicSinglePart(h, m),
+		payload(v)
+	{
+	}
+
+	void
+	BinaryViewPart::write(const StreamPtr & ms, Ice::Int) const
+	{
+		writeHeaders(headers, ms);
+		fputs("Content-Transfer-Encoding: base64\r\n", ms);
+		fprintf(ms, "Content-Type: %s\r\n\r\n",
+				mimetype.c_str());
+		base64(payload, ms);
+		fputs("\r\n", ms);
+	}
+
+	void
+	BinaryViewPart::base64(const std::basic_string_view<uint8_t> & input, FILE * ms,
+					const size_t maxWidth)
+	{
+		auto mime_encode_base64_block = [](auto & dest, const auto & src) {
+			if (src.length() >= 1) {
+				dest[0] = mime_base64[(src[0] & 0xFC) >> 2];
+				if (src.length() >= 2) {
+					dest[1] = mime_base64[((src[0] & 0x03) << 4) | ((src[1] & 0xF0) >> 4)];
+					if (src.length() >= 3) {
+						dest[2] = mime_base64[((src[1] & 0x0F) << 2) | ((src[2] & 0xC0) >> 6)];
+						dest[3] = mime_base64[((src[2] & 0x3F))];
+					}
+					else {
+						dest[2] = mime_base64[((src[1] & 0x0F) << 2)];
+					}
+				}
+				else {
+					dest[1] = mime_base64[(src[0] & 0x03) << 4];
+				}
+			}
+		};
+		
+		size_t l = 0;
+		for (size_t i = 0; i < input.length(); i += 3) {
+			if (maxWidth > 0 && l + 4 > maxWidth) {
+				fputs("\r\n", ms);
+				l = 0;
+			}
+
+			std::array<char, 4> bytes { '=', '=', '=', '=' };
+			mime_encode_base64_block(bytes, input.substr(i, 3));
+			fwrite(bytes.data(), bytes.size(),1, ms);
+			l += 4;
+		}
+		fputs("\r\n", ms);
+	}
+
+	BinaryCopyPart::BinaryCopyPart(const Headers & h, const std::string & m, std::vector<uint8_t> v) :
+		BinaryViewPart(h, m, { v.data(), v.size() }),
+		payload(std::move(v))
+	{
+	}
+
+
+	MultiPart::MultiPart(const Headers & h, const std::string & st, const Parts & p) :
+		BasicMultiPart(h, st, p)
+	{
+	}
+
+	void
+	MultiPart::write(const StreamPtr & ms, Ice::Int depth) const
+	{
+		writeHeaders(headers, ms);
+		fprintf(ms, "Content-Type: multipart/%s; boundary=\"%s%d\"\r\n\r\n",
+				subtype.c_str(), DIVIDER, depth);
+		for (const auto & p : parts) {
+			fprintf(ms, "--%s%d\r\n", DIVIDER, depth);
+			p->write(ms, depth + 1);
+		}
+		fprintf(ms, "--%s%d--\r\n", DIVIDER, depth);
+	}
+
+}
+
diff --git a/icetray/icetray/mimeImpl.h b/icetray/icetray/mimeImpl.h
new file mode 100644
index 0000000..235d747
--- /dev/null
+++ b/icetray/icetray/mimeImpl.h
@@ -0,0 +1,53 @@
+#ifndef ICETRAY_MIME_IMPL_H
+#define ICETRAY_MIME_IMPL_H
+
+#include <mime.h>
+#include <visibility.h>
+
+namespace IceTray::Mime {
+	class DLL_PUBLIC PartHelper {
+		protected:
+			static void writeHeaders(const Headers & headers, const StreamPtr & ms);
+	};
+
+	class DLL_PUBLIC TextPart : public BasicSinglePart, PartHelper {
+		public:
+			TextPart(const Headers &, const std::string &, const std::string &);
+
+			void write(const StreamPtr & ms, Ice::Int depth) const override;
+
+			static void quotedPrintable(const std::string_view & input, FILE * ms,
+					const size_t maxWidth = 74);
+
+			const std::string payload;
+	};
+
+	class DLL_PUBLIC BinaryViewPart : public BasicSinglePart, PartHelper {
+		public:
+			BinaryViewPart(const Headers &, const std::string &, const std::basic_string_view<uint8_t> &);
+
+			void write(const StreamPtr & ms, Ice::Int depth) const override;
+
+			static void base64(const std::basic_string_view<uint8_t> & input, FILE * ms,
+					const size_t maxWidth = 76);
+
+			std::basic_string_view<uint8_t> payload;
+	};
+
+	class DLL_PUBLIC BinaryCopyPart : public BinaryViewPart {
+		public:
+			BinaryCopyPart(const Headers &, const std::string &, std::vector<uint8_t>);
+
+			std::vector<uint8_t> payload;
+	};
+
+	class DLL_PUBLIC MultiPart : public BasicMultiPart, PartHelper {
+		public:
+			MultiPart(const Headers &, const std::string &, const Parts &);
+
+			void write(const StreamPtr & ms, Ice::Int depth) const override;
+	};
+}
+
+#endif
+
diff --git a/icetray/icetray/stream_support.h b/icetray/icetray/stream_support.h
new file mode 100644
index 0000000..4e01e7d
--- /dev/null
+++ b/icetray/icetray/stream_support.h
@@ -0,0 +1,17 @@
+#ifndef ICETRAY_STREAM_SUPPORT_H
+#define ICETRAY_STREAM_SUPPORT_H
+
+#include <cstdio>
+#include <memory>
+
+namespace IceTray
+{
+	class StreamPtr {
+		public:
+			operator FILE * () const { return f; }
+			FILE * const f;
+	};
+}
+
+#endif
+
diff --git a/icetray/unittests/Jamfile.jam b/icetray/unittests/Jamfile.jam
index 7486d04..655acb3 100644
--- a/icetray/unittests/Jamfile.jam
+++ b/icetray/unittests/Jamfile.jam
@@ -100,6 +100,16 @@ run
 	<library>testService
 	;
 
+run
+	testIceTrayMail.cpp
+	: -- :
+	fixtures/mail/multipart-alt-imgs.eml
+	fixtures/mail/multipart-alt.eml
+	fixtures/mail/simple.eml
+	:
+	<library>testCommon
+	;
+
 lib testService
 	:
 	testService.cpp
diff --git a/icetray/unittests/fixtures/mail/blank.png b/icetray/unittests/fixtures/mail/blank.png
new file mode 100644
index 0000000..bcaf83a
--- /dev/null
+++ b/icetray/unittests/fixtures/mail/blank.png
diff --git a/icetray/unittests/fixtures/mail/multipart-alt-imgs.eml b/icetray/unittests/fixtures/mail/multipart-alt-imgs.eml
new file mode 100644
index 0000000..f883d39
--- /dev/null
+++ b/icetray/unittests/fixtures/mail/multipart-alt-imgs.eml
@@ -0,0 +1,48 @@
+From: from <from@test.com>

+To: to <to@test.com>

+Date: Fri, 24 May 2019 22:19:54 +0000 (UTC)

+Return-path: <bounces@test.com>

+MIME-Version: 1.0

+X-Source: multipart_top

+Content-Type: multipart/alternative; boundary="//divider//0"

+

+--//divider//0

+X-Source: multipart_plain

+Content-Transfer-Encoding: quoted-printable

+Content-Type: text/plain; charset="utf-8"

+

+Simple text =C2=A3

+

+--//divider//0

+X-Source: multipart_html

+Content-Type: multipart/related; boundary="//divider//1"

+

+--//divider//1

+X-Source: multipart_html_main

+Content-Transfer-Encoding: quoted-printable

+Content-Type: text/html; charset="utf-8"

+

+<html lang=3D"en">

+<head>

+<title>=C2=A3</title>

+</head>

+<html>

+

+--//divider//1

+X-Source: multipart_html_img1

+Content-Transfer-Encoding: base64

+Content-Type: image/png

+

+iVBORw0KGgoAAAANSUhEUgAAAAsAAAALCAYAAACprHcmAAAABmJLR0QA/wD/AP+gvaeTAAAAJ0lE

+QVQYlWP8////fwbiwGomIhUyMDAwMIwqpo9iFgYGhtVEqj0BAAvPBjJ63HJVAAAAAElFTkSuQmCC

+

+--//divider//1

+X-Source: multipart_html_img2

+Content-Transfer-Encoding: base64

+Content-Type: image/png

+

+iVBORw0KGgoAAAANSUhEUgAAAAsAAAALCAYAAACprHcmAAAABmJLR0QA/wD/AP+gvaeTAAAAJ0lE

+QVQYlWP8////fwbiwGomIhUyMDAwMIwqpo9iFgYGhtVEqj0BAAvPBjJ63HJVAAAAAElFTkSuQmCC

+

+--//divider//1--

+--//divider//0--

diff --git a/icetray/unittests/fixtures/mail/multipart-alt.eml b/icetray/unittests/fixtures/mail/multipart-alt.eml
new file mode 100644
index 0000000..e199b58
--- /dev/null
+++ b/icetray/unittests/fixtures/mail/multipart-alt.eml
@@ -0,0 +1,27 @@
+From: from <from@test.com>

+To: to <to@test.com>

+Date: Fri, 24 May 2019 22:19:54 +0000 (UTC)

+Return-path: <bounces@test.com>

+MIME-Version: 1.0

+X-Source: multipart_top

+Content-Type: multipart/alternative; boundary="//divider//0"

+

+--//divider//0

+X-Source: multipart_plain

+Content-Transfer-Encoding: quoted-printable

+Content-Type: text/plain; charset="utf-8"

+

+Simple text =C2=A3

+

+--//divider//0

+X-Source: multipart_html

+Content-Transfer-Encoding: quoted-printable

+Content-Type: text/html; charset="utf-8"

+

+<html lang=3D"en">

+<head>

+<title>=C2=A3</title>

+</head>

+<html>

+

+--//divider//0--

diff --git a/icetray/unittests/fixtures/mail/simple.eml b/icetray/unittests/fixtures/mail/simple.eml
new file mode 100644
index 0000000..2b411c9
--- /dev/null
+++ b/icetray/unittests/fixtures/mail/simple.eml
@@ -0,0 +1,11 @@
+From: from <from@test.com>

+To: to <to@test.com>

+Date: Fri, 24 May 2019 22:19:54 +0000 (UTC)

+Return-path: <bounces@test.com>

+MIME-Version: 1.0

+X-Source: single_part

+Content-Transfer-Encoding: quoted-printable

+Content-Type: text/plain; charset="utf-8"

+

+Simple text =C2=A3

+

diff --git a/icetray/unittests/testIceTrayMail.cpp b/icetray/unittests/testIceTrayMail.cpp
new file mode 100644
index 0000000..ff2220a
--- /dev/null
+++ b/icetray/unittests/testIceTrayMail.cpp
@@ -0,0 +1,156 @@
+#define BOOST_TEST_MODULE TestIceTrayMail
+#include <boost/test/unit_test.hpp>
+#include <boost/test/data/test_case.hpp>
+
+#include <memstream.h>
+#include <mailServer.h>
+#include <mimeImpl.h>
+#include <fileUtils.h>
+#include <definedDirs.h>
+
+using namespace std::string_literals;
+using namespace IceTray::Mime;
+using namespace IceTray::Mail;
+using QPTD = std::tuple<std::string_view, std::string_view>;
+using B64TD = std::tuple<size_t, std::string_view>;
+
+BOOST_DATA_TEST_CASE(quotedPrintable, boost::unit_test::data::make<QPTD>({
+	{ "", "" },
+	{ "Simple string", "Simple string" },
+	{ " \t Leading whitespace", " \t Leading whitespace" },
+	{ "Trailing whitespace \t \n", "Trailing whitespace \t=20\r\n" },
+	{ "High byte values £ © ±", "High byte values =C2=A3 =\r\n=C2=A9 =C2=B1" },
+	{ "<html lang=\"en\">", "<html lang=3D\"en\">" }
+}), input, expected)
+{
+	AdHoc::MemStream ms;
+	TextPart::quotedPrintable(input, ms, 25);
+	BOOST_CHECK_EQUAL(expected, ms.sv());
+}
+
+BOOST_DATA_TEST_CASE(base64, boost::unit_test::data::make<B64TD>({
+	{ 0, "\r\n" },
+	{ 1, "iQ==\r\n" },
+	{ 2, "iVA=\r\n" },
+	{ 3, "iVBO\r\n" },
+	{ 4, "iVBORw==\r\n" },
+	{ 5, "iVBORw0=\r\n" },
+	{ 90,
+		"iVBORw0KGgoAAAANSUhEUgAA\r\n"
+		"AAsAAAALCAYAAACprHcmAAAA\r\n"
+		"BmJLR0QA/wD/AP+gvaeTAAAA\r\n"
+		"J0lEQVQYlWP8////fwbiwGom\r\n"
+		"IhUyMDAwMIwqpo9iFgYGhtVE\r\n" },
+	{ 113,
+		"iVBORw0KGgoAAAANSUhEUgAA\r\n"
+		"AAsAAAALCAYAAACprHcmAAAA\r\n"
+		"BmJLR0QA/wD/AP+gvaeTAAAA\r\n"
+		"J0lEQVQYlWP8////fwbiwGom\r\n"
+		"IhUyMDAwMIwqpo9iFgYGhtVE\r\n"
+		"qj0BAAvPBjJ63HJVAAAAAElF\r\n"
+		"TkSuQmA=\r\n" },
+}), input, expected)
+{
+	AdHoc::MemStream ms;
+	AdHoc::FileUtils::MemMap png(rootDir / "fixtures" / "mail" / "blank.png");
+	BinaryViewPart::base64(png.sv<uint8_t>().substr(0, input), ms, 24);
+	BOOST_CHECK_EQUAL(expected, ms.sv());
+}
+
+struct TestBase {
+	TestBase() :
+		e(std::make_shared<Email>()),
+#ifdef DUMP
+		dump(fopen("/tmp/dump.eml", "w")),
+#endif
+		fixtures(rootDir / "fixtures" / "mail")
+	{
+		e->from = {"from", "from@test.com"};
+		e->to = {"to", "to@test.com"};
+		e->subject = "subject";
+
+		auto commonHeaders = [](FILE * s) {
+			fputs("From: from <from@test.com>\r\n", s);
+			fputs("To: to <to@test.com>\r\n", s);
+			fputs("Date: Fri, 24 May 2019 22:19:54 +0000 (UTC)\r\n", s);
+			fputs("Return-path: <bounces@test.com>\r\n", s);
+		};
+		commonHeaders(ms);
+#ifdef DUMP
+		commonHeaders(dump);
+#endif
+	}
+	~TestBase()
+	{
+#ifdef DUMP
+		fclose(dump);
+#endif
+	}
+	EmailPtr e;
+	AdHoc::MemStream ms;
+#ifdef DUMP
+	FILE * dump;
+#endif
+	const std::filesystem::path fixtures;
+};
+
+const std::string text_content = "Simple text £\r\n";
+const std::string html_content = "<html lang=\"en\">\r\n"
+"<head>\r\n"
+"<title>£</title>\r\n"
+"</head>\r\n"
+"<html>\r\n";
+
+BOOST_FIXTURE_TEST_SUITE(base, TestBase);
+
+BOOST_AUTO_TEST_CASE(single_part)
+{
+	e->content = std::make_shared<TextPart>(Headers {
+		{ "X-Source", "single_part" }
+	}, "text/plain", text_content);
+	BasicMailServer::writeEmailContent(e, ms);
+	BOOST_CHECK_EQUAL(ms, AdHoc::FileUtils::MemMap(fixtures / "simple.eml").sv());
+}
+
+BOOST_AUTO_TEST_CASE(multipart_alt)
+{
+	auto text = std::make_shared<TextPart>(Headers {
+		{ "X-Source", "multipart_plain" }
+	}, "text/plain", text_content);
+	auto html = std::make_shared<TextPart>(Headers {
+		{ "X-Source", "multipart_html" }
+	}, "text/html", html_content);
+	e->content = std::make_shared<MultiPart>(Headers {
+		{ "X-Source", "multipart_top" }
+	}, "alternative", Parts { text, html });
+	BasicMailServer::writeEmailContent(e, ms);
+	BOOST_CHECK_EQUAL(ms, AdHoc::FileUtils::MemMap(fixtures / "multipart-alt.eml").sv());
+}
+
+BOOST_AUTO_TEST_CASE(multipart_alt_imgs)
+{
+	AdHoc::FileUtils::MemMap png(fixtures / "blank.png");
+	auto text = std::make_shared<TextPart>(Headers {
+		{ "X-Source", "multipart_plain" }
+	}, "text/plain", text_content);
+	auto img1 = std::make_shared<BinaryViewPart>(Headers {
+		{ "X-Source", "multipart_html_img1" }
+	}, "image/png", png.sv<uint8_t>());
+	auto img2 = std::make_shared<BinaryCopyPart>(Headers {
+		{ "X-Source", "multipart_html_img2" }
+	}, "image/png", std::vector<uint8_t>{ png.sv<uint8_t>().begin(), png.sv<uint8_t>().end() });
+	auto html = std::make_shared<TextPart>(Headers {
+		{ "X-Source", "multipart_html_main" }
+	}, "text/html", html_content);
+	auto htmlrel = std::make_shared<MultiPart>(Headers {
+		{ "X-Source", "multipart_html" }
+	}, "related", Parts { html, img1, img2 });
+	e->content = std::make_shared<MultiPart>(Headers {
+		{ "X-Source", "multipart_top" }
+	}, "alternative", Parts { text, htmlrel });
+	BasicMailServer::writeEmailContent(e, ms);
+	BOOST_CHECK_EQUAL(ms, AdHoc::FileUtils::MemMap(fixtures / "multipart-alt-imgs.eml").sv());
+}
+
+BOOST_AUTO_TEST_SUITE_END();
+