Hi Emi,
I have added your idea to the "InterMix Roadmap" and will discuss with the programmer, Flemming Funch:
0748 2 July 2014 / NEW What would be involved in having a five minute delay when a message is posted before any email send and before anyone except the author can see the message? If we implement this delay, we could also allow the user to delete the message during the delay period. We will have to disallow the author from replying to her own message during the 5 minute delay.
You may want to look at the list of items that Flemming is slowly working. I say slowly because I cannot afford many of his hours each week. I think we need to do a crowd-funding for the project. https://docs.google.com/document/d/15Z13tEfX7z7VBxYjWqAZHR38vxWNv_0_rM8QFq1GzzU/edit?usp=sharing
-- Roger