With Maildir the message GUID is typically the same as the Maildir base filename (i.e. everything before ':' character).
But what if I one day decide to convert my maildir's to mbox'es? I really plan to do such conversion in a while (as soon as I finish the indexing system).
mbox? or mdbox? With mbox there are no proper GUIDs, but Dovecot kind of fakes it by returning MD5 of specific headers as GUIDs (so not 100% reliable). With mdbox GUIDs work even better than with Maildir, the GUID is always stored in the message's metadata.
I'd like to use the best optimized one (mdbox), but there is a reason not to do that is when I use mbox or maildir I can see where given IMAP folder mails are stored, so, say, if I want to copy only one IMAP folder to some remote site, I just copy know dir or file. With mdbox this is different, I simply can not guess where my messages exactly are.
If it be possible to have per-IMAP-folders mdboxes, I love to use it. But from what I know and tried this is not way mdbox used to work, right?
Yours, Alexander Chekalin