I had this problem and fixed it by making sure my MANIFEST.MF has javax.activation.api in it's Dependencies

I get the same issue with Seam Mail and added this to WEB-INF/jboss-deployment-structure.xml.

<jboss-deployment-structure>
<deployment>
<dependencies>
<module name="javax.activation.api" />
</dependencies>
</deployment>
</jboss-deployment-structure>

And it does not work! I haven't tried the MANIFEST approach though. I prefer the jboss-deployment-structure.xml to wire external container includes and excludes.

Added Dependencies: javax.activation.api to MANIFEST.MF.

The same error still persists and does not solve the issue.

Deployments should have javax.activation.api automatically added already. This looks like it's failing to load the specific content type handler. What if you added the following line to the manifest:

Dependencies: javax.mail.api services export, javax.activation.api services export

It's just a hypothesis but I suspect that javax.activation.api isn't seeing the javax.mail.api content handlers. Adding this line should fix that but I'm not 100% on that either.

I had to do this to get it to work:
in /modules/javax/mail/api/main/module.xml
change the dependencies to:
<dependencies>
<module name="javax.activation.api" export="true"/>
<module name="javax.api"/>
</dependencies>

Then in /your.war/META-INF/MANIFEST.MF
Dependencies: javax.mail.api, javax.activation.api

This is working for me and I am now able to send email again.

Okay so at best we're looking at changing a module definition, at worst we need to patch one or two EE APIs. But either way it should be a small change so let's try to get it in for 7.0.1 if we can!

I have same problem, but in my case it goes for another module (mail subsystem) and no matter how I defined dependencies it does not work.
as i found out the problem is that activation api is trying to load something that is in javax.mail and that does not work as there is no dependency to javax.mail, even if i add it as dependency it does not work (not sure if circular dependency is allowed at all)

the only way I was able to make it work was a ugly ugly hack with adding mail-xxx.jar to javax.activation.api module as resource in that case it works like a charm

here http://forum.springsource.org/showthread.php?69180-Problems-sending-MIME-multipart-mails&s=8b04b3db93b33e93850c493776bb31ec it is a good explanation where the main problem is (javax libs itself) and what can be done

probably the best fix would be patching EE api jars..

Tomaz I think in your case what you want is a dependency on "javax.activation.api" pointing to "javax.mail.api" as you have, except you should also add services="import" to that dependency line. Yes, circular dependencies are allowed but only if you do NOT turn on export="true".

I retested mail (seam-mail 3.0.0.Alpha1) with as7.0.1 build 1519 (which is to my understanding the real 7.0.1 final). The following modification to activation module solves this issue:

Workaround: modules/javax/activation/api/main/module.xml

<module xmlns="urn:jboss:module:1.0" name="javax.activation.api">

    <dependencies>

        <module name="javax.api"/>

    </dependencies>

    <resources>

        <resource-root path="activation-1.1.1.jar"/>

        <resource-root path="mail-1.4.4.jar"/>

        <!-- Insert resources here -->

    </resources>

</module>

Copy modules/javax/mail/api/main/mail-1.4.4* modules/javax/activation/api/main/

This is not acceptable as a workaround. You should instead add a dependency on javax.mail.api in the <dependencies> section as I said; you probably also want services="import" on that line too. This should fix your problem just as well without resorting to copying JARs (which opens you up to CCEs).

i will take a look at this problem in the evening, and will try to find proper solution the way David explains...

David, if this is what you mean it doesn't work.

<module xmlns="urn:jboss:module:1.0" name="javax.mail.api">

    <dependencies>

        <module name="javax.activation.api" export="true"/>

        <module name="javax.mail.api" services="import"/>

        <module name="javax.api"/>

    </dependencies>

    <resources>

        <resource-root path="mail-1.4.4.jar"/>

        <!-- Insert resources here -->

    </resources>

</module>

Fix is a bit different, it is necessary to import addition files from META-INF of mail.jar.

javax.activation.api module must have depedencies defined like this:

<module xmlns="urn:jboss:module:1.0" name="javax.activation.api">

	<dependencies>

        <module name="javax.api" />

        <module name="javax.mail.api" >

        	<imports><include path="META-INF"/></imports>

        </module>	

	</dependencies>        

	 <resources>

        <resource-root path="activation-1.1.1.jar"/>

		<!-- Insert resources here -->

    </resources>

</module>

Awesome! It works!

Thank you

fixed by AS7-1177

How come this fix didn't make it for AS 7.0.2?

Without the above configuration Seam Mail 3 doesn't work.

http://seamframework.org/Seam3/MailModule

i am facing same problem on jboss-as-7.0.2.Final too

Fix is just in master and was not applied to 7.0.x version, it is in available in 7.1.x

then it is ok.

I do not understand why javax.activation.api depends on java mail...and I open the java mail modules.xml, it depends on java activation.

This fix is causing issue when exposing the javax.activation module as a capability to JBoss OSGi: The import is overriding the Manifest.mf
of javax.activation and instead making javax.mail visible, which later causes problems with OSGi bundles wishing to use the Java Mail API.

Do I need to raise a separate issue, or should this one be reopened ?

Ed,
this looks like to be issue related just to OSGI, as fix for this issue actually enabled sending mail at all.
open new issue for osgi subsystem.

Thanks Tomaz. I have raised a new issue
https://issues.jboss.org/browse/AS7-5187