What is needed for the messages, for those using Evernote in a business-like environment, is a prioritization of the messages, such as the one used in the Franklin Day Planner.
2 fields should be available for each message:
The user should be able to select sorting using one of the following:
Sort by Tag and ignore both Priority Group and Sequence Number.
Sort by Tag and then sort (always) by Priority Group then by Sequence Number, in each tag grouping.
Sort by Priority Group Then Sequence Number then Tag.
Sort by Priority Group Then Sequence Number ignoring any Tag.
The way this works is that we group our messages in priority groups, like A, B, C where A is what needs to be done today, B is what needs to be done in the next few days, and C is what would be good to do as soon as possible. Then within each group, we decide on the sequence to carry the different tasks/messages such as, A1 is something I must finish no matter what, prior to tackling A2 and A3. B1 is the next thing to do once I finish the A group, and C1, C2 etc... are the things to do at a later time if I can.
Of course, the user can ignore these priority setting (that are available for EACH and EVERY message) and continue using Evernote as usual.