KDE PIM does not display one's own email address and name, but instead replaces it with "me".
This is certainly a feature appreciated by many users, however in a language like German this looks very awkward (for details see https://bugs.kde.org/show_bug.cgi?id=469713). So it would be very desirable to be able to switch off that feature.

I dug through the code to find out that it is a feature implemented in messagecore's stringutil. 
It is quite easy to add a switch, e.g. like this to messagelib/messagecore/src/utils/stringutil.cpp

Change line 443 from

const bool foundMe = onlyOneIdentity && (im->identityForAddress(prettyAddressStr) != KIdentityManagementCore::Identity::null());

to

const bool foundMe = !(MessageCore::MessageCoreSettings::self()->displayOwnIdentity()) && onlyOneIdentity && (im->identityForAddress(prettyAddressStr) != KIdentityManagementCore::Identity::null());


and in messagelib/messagecore/src/settings/messagecore.kcfg add an item like this:

<entry name="displayOwnIdentity" type="Bool">
      <default>false</default>
    </entry>

I added it to the General group, but I'm unsure whether this is the correct approach. Moreover I'm not sure whether the messagecore settings is the right spot for such a switch.
To test it, I set the default to true and opened an email sent by me (or sent to me) in kmail2. Worked as expected.
There should also be an easy way to change the setting via the CLI, isn't there?
In addition,  it would be nice to have a UI to toggle this setting. There seems to be a convenient way in messageviewer/src/ui/settings.ui, but I could not come up with an equivalent for messagecore.
Or is having that setting in messagelib/messageviewer/src/settings/messageviewer.kcfg.in a better idea? (after all it's about displaying a message's header)