JavaMail cannot be used as it was in JBossAS 6 and earlier.

1) I tried as in JBoss 6:
@Resource(mappedName = "java:Mail")
private Session mailer;

... and got this logging info within the Arquillian tests:
11:12:08,454 INFO [org.jboss.as.server.controller] (pool-1-thread-48) Deployment of "test.ear.ear" was rolled back with failure message

{"Services with missing/unavailable dependencies" => ["jboss.naming.context.java.comp.\"test.ear\".test.KundenverwaltungListener.\"env/de.swe2.kundenverwaltung.service.KundenverwaltungListener/mailer\".jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.KundenverwaltungListener.8","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.Dao.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.KundenverwaltungListener.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.KundenverwaltungResourceImpl.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.ValidationService.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.Kundenverwaltung.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.Artikelverwaltung.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.FileStore.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.RolesService.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.BestellverwaltungResourceImpl.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.PasswordService.START","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".jndiDependencyService","jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.Bestellverwaltung.START"]}

11:12:08,468 INFO [org.jboss.jpa] (MSC service thread 1-1) stopping Persistence Unit Service 'test.ear.ear/test.jar#swe2Persistence'
11:12:08,470 INFO [org.jboss.weld] (MSC service thread 1-1) Stopping weld service

2) I tried
@Resource
private Session mailer;

... and got this logging info within the Arquillian tests:
11:09:20,085 INFO [org.jboss.as.server.controller] (pool-1-thread-46) Deployment of "test.ear.ear" was rolled back with failure message

{"Services with missing/unavailable dependencies" => ["jboss.deployment.subunit.\"test.ear.ear\".\"test.jar\".component.KundenverwaltungListener.START"]}

11:09:20,094 INFO [org.jboss.jpa] (MSC service thread 1-2) stopping Persistence Unit Service 'test.ear.ear/test.jar#swe2Persistence'
11:09:20,098 INFO [org.jboss.weld] (MSC service thread 1-2) Stopping weld service