I'm having trouble with Gmail!

Is anyone else here using Gmail? Because I’m staring at this screenshot and I can't for the life of me figure out what's going wrong:
I feel like I've tried absolutely everything under the sun, from nuking the app and reinstalling the exact same version to trying out the latest update, but nothing sticks. I even went as far as performing a full system restore since I had a backup saved from back when everything was actually working perfectly, yet here I am facing the exact same damn issue...

Uninstall Gmail, reveal your hidden files, then head over here:

For XP

C:\Users\{Profile Name}\Local Settings\Application Data\Gmail\

For 7

WINDOWS 7: C:\Users\Your Profile Name (Logon Name)\AppData\Local Settings\Gmail

Wipe everything inside that folder, assuming you don't actually care about your old message history, because if those messages actually matter to you, then

C:\Users\Your Profile Name (Logon Name)\AppData\Local Settings\Gmail\identity - that's where the saved messages live, so just grab what you need before clearing out the rest of the Gmail folder...
Reinstall Gmail and see if things are back to normal

I went through all the motions, completely wiped everything and reinstalled the exact same latest version of the app, but I’m still staring at the same damn problem, and I already told you I even rolled my entire system back to the day I first installed it...

Lately, I’ve been running into this absolute headache with Gmail again, where it just refuses to send anything from any single address I try using. It isn't just me, either; everyone I've helped set up on my system is hitting this exact same wall because the whole thing has just flat-out quit on us. It's completely stopped working, and all I get is this error message shown in the picture:

Maybe the issue is that special character in "home." Try swapping it out for something else (like just "home" without the accent).

I honestly can't believe it, it's actually happening... thanks, man...