A method in a communication network of delivering messages associated with an information exchange service between a first entity (200,300,400) and a second entity (201,301,401), said method comprising the following steps, executed by the first entity (200,300,400): - processing (2:1,3:1,4:3) a message associated with said information exchange service, said message comprising data content and a request for versioning, wherein said versioning comprises associating each version of said data content of said message with a data identifier, identifying said version, - determining if the data content has already been delivered to the second entity (201,301,401), and - transmitting (2:2,3:2,4:4) said message, unchanged, to the second entity (201,301,401) in case said data content has not already been delivered to the second entity (201,301,401), or - transmitting (2:12,3:12,4:14) a modified message to the second entity (201,301,401) in case the data content has already been delivered to the second entity (201,301,401), said modified message comprising said data identifier but no data content, and - storing (2:5) said data content and said associated data identifier in a cache of said first entity (200,300,400) subsequent to receiving (2:4) a response message from said second entity (201,301,401), verifying that said message comprising said data content has been successfully delivered to and stored at a cache of said second entity (201,301,401), characterized in that said response message comprises an indication of total capacity of the cache of said second entity (201,301,401) and each subsequent response messages comprise an indication of the remaining capacity of the cache of said second entity (201,301,401). - processing (2:1,3:1,4:3) a message associated with said information exchange service, said message comprising data content and a request for versioning, wherein said versioning comprises associating each version of said data content of said message with a data identifier, identifying said version, - determining if the data content has already been delivered to the second entity (201,301,401), and - transmitting (2:2,3:2,4:4) said message, unchanged, to the second entity (201,301,401) in case said data content has not already been delivered to the second entity (201,301,401), or - transmitting (2:12,3:12,4:14) a modified message to the second entity (201,301,401) in case the data content has already been delivered to the second entity (201,301,401), said modified message comprising said data identifier but no data content, and - storing (2:5) said data content and said associated data identifier in a cache of said first entity (200,300,400) subsequent to receiving (2:4) a response message from said second entity (201,301,401), verifying that said message comprising said data content has been successfully delivered to and stored at a cache of said second entity (201,301,401), characterized in that said response message comprises an indication of total capacity of the cache of said second entity (201,301,401) and each subsequent response messages comprise an indication of the remaining capacity of the cache of said second entity (201,301,401).