A method for supporting across-domain messaging in a transactional middleware machine environment, comprising: sharing, by network file system, a global resource containing machine identifiers, group numbers, transaction management server services information and a list of domain sequence numbers for a plurality of domains in a domain group, wherein each domain in the domain group is associated with a unique identifier represented by a domain sequence number and the machine identifiers and group numbers are unique with each domain; storing, by each domain in the domain group, the global resource in a service table stored in local shared memory of the domain; importing, via a transaction domain, one or more services from a remote transaction domain, wherein said one or more services are registered in the service table stored in local shared memory of the transaction domain and wherein the transaction domain and the remote transaction domain are in the domain group; finding, via a client in the transaction domain, from the service table, a remote server in the remote transaction domain that provides said one or more services reconstructing, via the transaction domain, each machine identifier in the global resource by using the domain sequence number as part of the machine identifier and combining the group number with the domain sequence number; determining, via the client, one or more transaction management servers in both the transaction domain and the remote transaction domain that are involved in a transaction by combining the domain sequence number and the group number for each of the transaction domain and the remote transaction domain; and sending, via the client and using the one or more transaction management servers, a message directly to the remote server to invoke said one or more services bypassing one or more domain gateway servers in both the transaction domain and the remote transaction domain that connect the transaction domain and the remote transaction domain. sharing, by network file system, a global resource containing machine identifiers, group numbers, transaction management server services information and a list of domain sequence numbers for a plurality of domains in a domain group, wherein each domain in the domain group is associated with a unique identifier represented by a domain sequence number and the machine identifiers and group numbers are unique with each domain; storing, by each domain in the domain group, the global resource in a service table stored in local shared memory of the domain; importing, via a transaction domain, one or more services from a remote transaction domain, wherein said one or more services are registered in the service table stored in local shared memory of the transaction domain and wherein the transaction domain and the remote transaction domain are in the domain group; finding, via a client in the transaction domain, from the service table, a remote server in the remote transaction domain that provides said one or more services reconstructing, via the transaction domain, each machine identifier in the global resource by using the domain sequence number as part of the machine identifier and combining the group number with the domain sequence number; determining, via the client, one or more transaction management servers in both the transaction domain and the remote transaction domain that are involved in a transaction by combining the domain sequence number and the group number for each of the transaction domain and the remote transaction domain; and sending, via the client and using the one or more transaction management servers, a message directly to the remote server to invoke said one or more services bypassing one or more domain gateway servers in both the transaction domain and the remote transaction domain that connect the transaction domain and the remote transaction domain.