Ethics of/rules regarding submitting multiple presubmission inquiries It is well-established (and typically spelled-out in journals' instructions to authors) that is unacceptable to submit a single manuscript to multiple journals for peer review simultaneously. However, the rules for presubmission inquiries (which are essentially cover letters asking whether the journal would be interested in reviewing a given paper) are not clear to me; a presubmission inquiry does not constitute a formal submission.

Is it permissible to submit a presubmission inquiry regarding a single manuscript to more than one scientific journal? 

Is it unethical to do so? 



Further details on what presubmission inquiries are:

Presubmission inquiries are relatively common in genetics and biology. From the Nature website:


  Presubmission enquiries are provided purely as a service to authors
  (for example, to see if a manuscript is likely to be of interest to
  the journal) and are not compulsory... Presubmission enquiries are not
  required for Articles or Letters, and can be difficult to assess
  reliably; Nature editors cannot make an absolute commitment to have a
  contribution refereed before seeing the entire paper. Entire papers
  should not be sent as presubmission enquiries, but should be formally
  submitted through our online submission system.
As an author I have done two presubmissions in the past. I do not know how they are handled by editors, but as an associate editor myself I gather they are informally skimmed by 1-2 editors within hours after submission. This means it is unlikely some "multiple presubmission" would be detected and I have never seen specific rules about priorities in presubmissions. 

Thus I think one is safe from editorial action if "caught" in multiple presubmission enquiries. However I believe it will not be seen with good eyes by a handling editor, and might leave a bad impression. 

Thus I would not recommend doing it. Particularly as an editorial answer usually comes in less than 48h.