Are generalized recommendation letters bad? Sometimes online application systems ask for uploading recommendation letters as supplementary documents (scanned copies). In this case, it is possible to get general recommendation letters (addressed as To Whom It May Concern) and submit them for different applications.


Is it bad to submit a recommendation letter, which has not been addressed for a specific application? Assume that the content will be the same.
If it is OK, is it bad to attach some recommendation letters for an application when it is not requested?
First, as wsc says, you should not be uploading the letters yourself.  Usually there's someone in your dept. who can accept letters and send them out if there's no way for the letters to be uploaded directly.

Second, senior letter writers already spend a lot of their own valuable time writing letters for dozens of people.  Asking them to write separate letters for dozens and dozens of applications for each person is completely unreasonable.  In Math for research jobs in the US, letters for job applicants are not school specific.  (Though they do usually say "postdoc" or "tenure track position" since obviously a strong postdoc candidate would often be a weak TT candidate.)

(For teaching letters for liberal arts schools my impression is that the situation is somewhat different and some specialization may be expected.  But I don't have first-hand knowledge.  Of course, for those letters, it's less likely that one person is writing 50 letters a year.)