After creating an additional sent-box (i.e. by selecting "Create 
Mailbox" in the dropdown for the "Save sent mail" setting when 
creating a new identity)

1) the new sent-mail box is shown with the name given when created
2) change language of the UI, and change back to previous value
3) the new sent-mail box is "renamed" to "Sent"
4) as a result there are two special-mailbox-folders displayed with 
the same name ("Sent")

As it is only a display problem, priority is low. As it makes the 
application-use dysfunctional, priority is high.
So: medium


There are many solutions thinkable. i.e:
  * At the moment it is impossible to change or disable folder-name 
translations on user-side. (could be a fix)
  * At the moment the is no simple help - resource (config example) 
for configuring a solution on server side  (could be a fix)

  * A reasonable quick-fix could be for instance to show both: the 
original (real) folder-name (in brackets) along with the translated 
display-name: in case real-name is different to display-name  (&& and 
there is more than one special-mail-boxes of this kind ?).