Geary no have option to remove last account

Do you have more than one account? Geary currently doesn't allow you to remove the final account.

i have only one account.

That's a current limitation of Geary. I've reported it upstream at http://redmine.yorba.org/issues/6475

I've the same problem, i unistalled geary and the preferences didn't delete.

There is a workaround to remove undesired accounts from Geary.
After you did
sudo apt-get remove geary
do the following.
In your local directory, go to .local | geary | and manually delete any accounts you do not want to have.
When you reinstall Geary, it will only see the accounts you left in .local/geary.

I have not tested the solution just deleting the accounts without removing geary, and I will leave that as a homework assignment to the next person.
--

I didn't run into any problems by simply deleting the accounts without reinstall geary.

rm ~/.local/share/geary/*

Same here, I kill the geary process (kill -15 <process id> )to avoid any locked file and remove the account under .local/share/geary successsfully

This bug is still there. I would like to delete the one account.