Is your feature request related to a problem? Please describe.
Yes, my feature request relates to a problem I frequently encounter. Specifically, I'm always frustrated when the order of my mail messages with the same date becomes inconsistent whenever I delete some of these messages.

Here is an illustration:

If I delete the email on the fifth line, the order of the subsequent emails will be messed up.

Describe the solution you'd like
Sort according to mu4e-search-sort-field, and then by message id.