- Easiest way to deal with message locking is to avoid 7th edition mailbox (mbox) format
- Use mailbox directory instead, but can use folders
- One message per file
- Some typical POP3 enhancements not applicable
- However, so long as lock mechanism is shared by LDA & IMAP server, can avoid file locking and use database instead
For IMAP, you need message locking anyway, so the use of a mailbox directory format is natural, although I still believe that file locking with a mailbox directory requires an excessive amount of work and should instead be pulled into a proper database (more on this later).