use default settings for setpref

I would like to send an email from MATLAB.

To do so, I have to configure some prefs with setpref, e.g.

setpref('Internet', 'SMTP_Server', ...)

How to do so once, such that MATLAB remembers the settings after I restart the application?

One possible solution I can think of is to write them down in my startup.m.

Is there any other possibilities, as I would like to not expose my email password, even if I think that my startup.m keeps private.