Mail: Real vs. Fake Mails

Advantages: Real mail client

Realistic user experience (if working how intended) (MD: and the "if" is the key word here!)
More "depth" in gameplay
Less effort for development (MD: please explain this in our meeting)
Spam also part of real-world work (MD: Is this really an advantage? Seems to me that spam is, wherever possible, excluded from our working lives through institutional mail settings. I suspect many users would be uncomfortable about having to deal with spam settings in order to play our game.)

Fail-proof (no spam issues)
User doesn't have to leave application / medium
More control over how mails/notifications are displayed
Mailing functionality can be implemented precisely as requried, not more or less
(MD: does the fake client reduce the possibility that things could go wrong in the interface between a real mail client and the research notebook?)
(MD: can we think of any disadvantages of the fake male client–regardless of whether we use a real mail client?)