API mailboxes and emails count

[cyd01]

Please consider to add a new API command to retrieve the list of the current mailboxes, and for each, the number of emails.

The list could be under route GET /api/v1/mailbox/

Thanks

[jhillyerd]

Unfortunately, this isn't feasible with the current storage design -- Inbucket has to walk the file tree to discover what mailboxes exist. It could take seconds or even minutes depending on how many mailboxes there are and how fast the disk is.

At some point I'd like to add a embedded database or key/value store to enable this and searching, so it may be possible in the long term.