Past year, I’ve been getting more and more angry about this, which made me decide do implent a workaround: a Windows Mobile SMTP proxy called MobileHermes. Completely free and licenced under the GPL, open source!

The SMTP proxy is a very small application (around 30K) written in C# using Visual Studio 2008. You can keep it running in the background of your WM device, it will do no harm nor eat much memory. After installing MobileHermes, it will show up in your application menu. Start it and look at the “Configuration” tab, which shows the three most important configuration options (among a few others):

• SMTP server hostname: specify your SMTP server hostname, e.g.: smtp.gmail.com
• SMTP server port: specify your SMTP server port, e.g.: 587
• Require secure communication: check this option whenever you only want to allow communication with the SMTP server using an encrypted connection. Note that MobileHermes doesn’t implement any kind of encryption, it will only refuse proxying data over a plain communication channel.

After setting these three options on the “Configuration” tab, you might want to press the button which says “Save configuration”. Afther that, start the proxy by pressing the button labelled “Start SMTP proxy” on the “Control” tab. Next, press button “Test SMTP proxy” to test whether your settings will actually allow you to connect to a mail server.

Last, but not least: you’ll have to configure your mail client (probably the built-in Windows Mobile one) to use “localhost” as SMTP server. To do that, open the mail client and click “Menu”, “Tools”, “Options…” and select the mail account to edit. Click through all options until you see “Outgoing (SMTP) mail server”. That’s where you configure “localhost” (without any port configuration, just “localhost”). Most probably, you’d want to check the checkboxes “Outgoing server requires authentication” and “Use the same user name and password for sending e-mail”, but that completely depends on the configuration of your external SMTP server.

Now, try to send a message from the mail client. If everything works like it’s supposed to, you’ll see two lines popping up on the status log of MobileHermes:

17:04:12 Accepted new connection from 127.0.0.1:1446
17:04:20 Connection from 127.0.0.1:1446 closed.

Since communication between your mail client and the external SMTP server might be encrypted, MobileHermes doesn’t show you any detailed information about the connection. You might want to check “show detailed log information” on the “Configuration” tab to see more details about the data coming in and going out.

That’s it! To be able to use MobileHermes, you’ll have to install Microsoft’s .NET Compact Framework version 3.5 (or higher). After having installed that, you can install MobileHermes by downloading the CAB-file to your mobile device from: https://guust.tuxes.nl/~bas/MobileHermes/MobileHermes-1.0.cab and opening it. If you’re interested in the source code (don’t expect it to be very neat, optimal or bug-free!), you can download that too: https://guust.tuxes.nl/~bas/MobileHermes/MobileHermes-1.0.rar. Feel free to modify it, but be aware of the fact MobileHermes is licenced under the GPL!

It’s very hard to find out what exactly is going wrong. The only thing Windows Mobile tells you is:

The message(s) could not be sent. Check that you have network coverage and that your account information is correct. Then try sending again.

According to the Postfix logs, Windows Mobile disconnects directly after having established a TLS connection (using StartTLS). My transparent SMTP proxy for Windows Mobile confirms this observation:

20:48:40 s->c: 220 guust.tuxes.nl ESMTP Postfix (Debian/GNU)
20:48:40 c->s: EHLO Inbox
20:48:40 s->c: 250-guust.tuxes.nl
250-PIPELINING
250-SIZE 52428800
250-VRFY
250-ETRN
250-AUTH DIGEST-MD5 CRAM-MD5
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
20:48:41 c->s: QUIT
20:48:41 s->s: 221 2.0.0 Bye

Note the “QUIT” issued by the client directly after Postfix’ 250 response to the client’s EHLO.

Entirely disabling authentication solves the communication problems, indicating that there might be a compatibility problem with the authentication mechanisms offered by Postfix (or, actually, by SASL). I’m using SASL authentication, configured in /etc/postfix/sasl/smtpd.conf:

pwcheck_method: auxprop
auxprop_plugin: sasldb
log_level: 3
mech_list: cram-md5 digest-md5

These mechanisms work perfectly with regular modern MUA’s (Mail User Agents) like Mozilla Thunderbird and Outlook… Might Windows Mobile be unable incapable of using cram-md5 or digest-md5? The answer to that question turns out to be “YES”. After adding “login” to the mech_list, Windows Mobile didn’t complain anymore!

Now, there’s still the problem that it seems to be impossible to specify an outgoing SMTP server port in the Windows Mobile messaging tool. Even specifying “guust.tuxes.nl:587″ will not prevent WM from connecting to port 25 on host “guust.tuxes.nl”. I’m on the road a lot and sometimes I’m using my phone’s internal WLAN radio to connect to the internet. Most providers (both mobile and internet service providers) restrict outbound traffic on port 25 as an anti-spam measure, should I reconfigure my mail client everytime I want to send an e-mail?

No! That’s why I wrote an SMTP proxy for Windows Mobile, called “MobileHermes”. It sits in the background, listening on port 25 and proxies traffic to a predefined mail server on a predefined port (which can be other than 25). Final version to be released soon. Very soon.

Error messages you might encounter are like: “an error occurred when connecting to the host” and “the launch requires
at least one data collector to be selected”.

Actually (you wouldn’t say!), TPTP is complaining about not being able to connect to the Integrated Agent Controller. That’s the part of TPTP responsible for monitoring your application and sending information to Eclipse. Most probably, TPTP was installed to your Eclipse plugins directory (“/home/bas/.eclipse/org.eclipse.platform_3.5.0_155965261/plugins” in my case).

Check out whether you’re able to start the IAC by hand, this is what happened when I tried to do so:

$ ~/.eclipse/org.eclipse.platform_3.5.0_155965261/plugins/org.eclipse.tptp.platform.ac.linux_em64t_4.4.201.v200909111644/agent_controller/bin/ACStart.sh

Starting Agent Controller.
ACServer: error while loading shared libraries: libstdc++.so.5: cannot open shared object file: No such file or directory
ACServer failed to start.

Clearly, the Agent Controller was built against old C++ libraries which were no longer available on my system (Ubuntu 9.10 Karmic Koala, amd64). The package “libstc++5” from Ubuntu 9.04 Jaunty Jackalope contains the missing library, installing the package will solve the problem:

wget http://mirrors.kernel.org/ubuntu/pool/universe/g/gcc-3.3/libstdc++5_3.3.6-17ubuntu1_amd64.deb
sudo dpkg -i libstdc++5_3.3.6-17ubuntu1_amd64.deb

Now, trying to manually start the IAC should generate an entirely different message, like this:

$ ~/.eclipse/org.eclipse.platform_3.5.0_155965261/plugins/org.eclipse.tptp.platform.ac.linux_em64t_4.4.201.v200909111644/agent_controller/bin/ACStart.sh

Starting Agent Controller.
sh: ./SetConfig.sh: not found
Error reading the Agent Controller configuration file. Please check for valid configuration.Could not start Agent Controller.ACServer failed to start.

Although it looks a bit dramatic, it’s nothing to get too worried about. Just restart Eclipse and try the “Profile” button once more. TPTP should work like a charm!