INSTALL.maildir.md (2377B)
1 This file points out some reasons that you might want to switch from 2 mbox format to a new format, maildir. 3 4 5 1. The trouble with mbox 6 7 The mbox format -- the format of ~user/Mailbox, understood by BSD Mail 8 and lots of other MUAs -- is inherently unreliable. 9 10 Think about it: what happens if the system crashes while a program is 11 appending a new message to ~user/Mailbox? The message will be truncated. 12 Even worse, if it was truncated in the middle of a line, it will end up 13 being merged with the next message! Sure, the mailer understands that it 14 wasn't successful, so it'll try delivering the message again later, but 15 it can't fix your corrupted mbox. 16 17 Other formats, such as mh folders, are just as unreliable. 18 19 qmail supports maildir, a crashproof format for incoming mail messages. 20 maildir is fast and easy for MUAs to use. Even better, maildir works 21 wonders over NFS -- see below. 22 23 I don't want to cram maildir down people's throats, so it's not the 24 default. Nevertheless, I encourage you to start asking for maildir 25 versions of your favorite MUAs, and to switch over to maildir as soon as 26 you can. 27 28 29 2. Sun's Network Failure System 30 31 Anyone who tells you that mail can be safely delivered in mbox format 32 over NFS is pulling your leg -- as explained above, mbox format is 33 inherently unreliable even on a single machine. 34 35 Anyway, NFS is the most unreliable computing environment ever invented, 36 and qmail doesn't even pretend to support mbox over NFS. 37 38 You should switch to maildir, which works fine over NFS without any 39 locking. You can safely read your mail over NFS if it's in maildir 40 format. Any number of machines can deliver mail to you at the same time. 41 (On the other hand, for efficiency, it's better to get NFS out of the 42 picture -- your mail should be delivered on the server that contains your 43 home directory.) 44 45 Here's how to set up qmail to use maildir for your incoming mail: 46 47 ``` 48 % maildirmake $HOME/Maildir 49 % echo ./Maildir/ > ~/.qmail 50 ``` 51 52 Make sure you include the trailing slash on Maildir/. 53 54 The system administrator can set up Maildir as the default for everybody 55 by creating a maildir in the new-user template directory and replacing 56 ./Mailbox with ./Maildir/ in /var/qmail/rc. 57 58 Until your MUA supports maildir, you'll probably want to convert maildir 59 format to (gaaack) mbox format. I've supplied a maildir2mbox utility 60 that does the trick.