AFAICT, all distinct email sources are currently stored in the database, because the the id is derived from a hash of the source. (*)
However, that does not mean that they are recoverable. The current database design requires that source entries are retrieved via the corresponding mbox entry. If a second email is received that hashes to the same mbox index, the pointer back to the existing source entry will be overwritten. Such duplicates are not unknown; mail transport glitches can result in duplication of email content (but different ezmlm archive numbers and some other headers). In such cases, it is no longer possible to recover the original source. I think this could be fixed, but until it is, I don't think Pony Mail can be considered as a complete archival application, as it does not give access to all the emails received by a mailing list. Sebb (*) discounting hash collisions, which should be vanishingly small
