How to debug 'ignoring non-mail file' issues

[Perttu Luukko]

On 2014-08-31 07:41:42, David Bremner wrote:
> Perttu Luukko <perttu.luukko at iki.fi> writes:
> > The vast majority of these ignored mails are not ignored after I
> > transfer them with offlineimap to another computer. I can non-ignore
> > these files probably by copying the renamed file back to the mail
> > server, so this is fixable. Offlineimap shouldn't mess with the file's
> > contents, so is there something that can cause notmuch to ignore a file
> > based on its name?
> 
> The most likely cause is that the files are mboxes, whether intentional
> or not.  In particular if they start with a "From " (note the lack of :)
> and contain a second "From " at the beginning of a line later in the
> file. In this case something like sed can replace the initial 
> "From " with "X-Envelope-From: ".
> 
> I agree that the error message could be more informative in this case.

No, the mails do contain "From: " with the appropriate colon. If I
understood correctly notmuch returns the same "not mail" return code
both when the essential headers are missing (so the file probably really
isn't mail) and when GMime fails to parse the message. I think it would
be a good idea to give a different warning in the latter case.

If the files really are ignored because of GMime it also explains why so
much more files are ignored on my mail provider's server than on my
laptop. The server probably has an older version of GMime. I'll upgrade
and see if that makes a difference.

-- 
Perttu