In version 2.0 we changed the "identification" of MailMe messages. We no longer use a subject prefix, instead messages from MailMe are simply sent from "MailMe".
The change means that the messages look better in your inbox, as we utilize the "From" column which we did not do before. However, if you use inbox rules, and had them set up to react on the "MailMe:" prefix, these rules need to be updated.
Let us know how this works out for you. Thanks!