Try the URL http://confluence.atlassian.com/spaces/viewmailarchive.action when using Postgres.

You get:

org.springframework.jdbc.BadSqlGrammarException: Bad SQL grammar [] in task 'Hibernate operation'; nested exception is org.postgresql.util.PSQLException: ERROR: operator does not exist: bigint = bytea
org.postgresql.util.PSQLException: ERROR: operator does not exist: bigint = bytea
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse()Ljava/sql/SQLException;(QueryExecutorImpl.java:1512)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(Lorg/postgresql/core/ResultHandler;I)V(Optimized Method)
at org.postgresql.core.v3.QueryExecutorImpl.execute(Lorg/postgresql/core/Query;Lorg/postgresql/core/ParameterList;Lorg/postgresql/core/ResultHandler;III)V(Optimized Method)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(Lorg/postgresql/core/Query;Lorg/postgresql/core/ParameterList;I)V(Optimized Method)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(I)Z(AbstractJdbc2Statement.java:346)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery()Ljava/sql/ResultSet;(AbstractJdbc2Statement.java:250)
at com.caucho.sql.UserPreparedStatement.executeQuery()Ljava/sql/ResultSet;(UserPreparedStatement.java:100)
at com.caucho.sql.UserPreparedStatement.executeQuery()Ljava/sql/ResultSet;(UserPreparedStatement.java:100)
at net.sf.hibernate.impl.BatcherImpl.getResultSet(Ljava/sql/PreparedStatement;)Ljava/sql/ResultSet;(BatcherImpl.java:89)
at net.sf.hibernate.loader.Loader.getResultSet(Ljava/sql/PreparedStatement;Lnet/sf/hibernate/engine/RowSelection;Lnet/sf/hibernate/engine/SessionImplementor;)Ljava/sql/ResultSet;(Loader.java:880)
at net.sf.hibernate.hql.QueryTranslator.iterate(Lnet/sf/hibernate/engine/QueryParameters;Lnet/sf/hibernate/engine/SessionImplementor;)Ljava/util/Iterator;(QueryTranslator.java:868)
at net.sf.hibernate.impl.SessionImpl.iterate(Ljava/lang/String;Lnet/sf/hibernate/engine/QueryParameters;)Ljava/util/Iterator;(SessionImpl.java:1619)
at net.sf.hibernate.impl.QueryImpl.iterate()Ljava/util/Iterator;(QueryImpl.java:29)
at com.atlassian.confluence.mail.persistence.dao.hibernate.HibernateMailDao$3.doInHibernate(Lnet/sf/hibernate/Session;)Ljava/lang/Object;(HibernateMailDao.java:115)
at org.springframework.orm.hibernate.HibernateTemplate.execute(Lorg/springframework/orm/hibernate/HibernateCallback;)Ljava/lang/Object;(HibernateTemplate.java:200)
at com.atlassian.confluence.mail.persistence.dao.hibernate.HibernateMailDao.findMailTotal(Lcom/atlassian/confluence/spaces/Space;)I(HibernateMailDao.java:109)
at jrockit.reflect.NativeMethodInvoker.invoke0(Ljava/lang/Object;ILjava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;(Unknown Source)
at jrockit.reflect.NativeMethodInvoker.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at jrockit.reflect.VirtualNativeMethodInvoker.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at java.lang.reflect.Method.invoke(Ljava/lang/Object;[Ljava/lang/Object;I)Ljava/lang/Object;(Optimized Method)
at org.springframework.aop.framework.AopProxyUtils.invokeJoinpointUsingReflection(Ljava/lang/Object;Ljava/lang/reflect/Method;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(Ljava/lang/Object;Ljava/lang/reflect/Method;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at $Proxy20.findMailTotal(Lcom/atlassian/confluence/spaces/Space;)I(Unknown Source)
at com.atlassian.confluence.mail.DefaultMailContentManager.findMailTotal(Lcom/atlassian/confluence/spaces/Space;)I(DefaultMailContentManager.java:66)
at jrockit.reflect.NativeMethodInvoker.invoke0(Ljava/lang/Object;ILjava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;(Unknown Source)
at jrockit.reflect.NativeMethodInvoker.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at jrockit.reflect.VirtualNativeMethodInvoker.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at java.lang.reflect.Method.invoke(Ljava/lang/Object;[Ljava/lang/Object;I)Ljava/lang/Object;(Optimized Method)
at org.springframework.aop.framework.AopProxyUtils.invokeJoinpointUsingReflection(Ljava/lang/Object;Ljava/lang/reflect/Method;[Ljava/lang/Object;)Ljava/lang/Object;(Optimized Method)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint()Ljava/lang/Object;(Optimized Method)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed()Ljava/lang/Object;(Optimized Method)
at com.atlassian.confluence.util.profiling.SpringProfilingInterceptor.invoke(Lorg/aopalliance/intercept/MethodInvocation;)Ljava/lang/Object;(Optimized Method)