(Of course, the real solution is to forget about /var/mail and use Maildir or dbox. – 2014‑08‑22)
To speed up mail checks, I access Dovecot imapd at my server through a SSH tunnel, which executes [dovecot --exec-mail imap] over the (multiplexed) SSH connection.
Being launched like this, Dovecot doesn't have the necessary access to create dotlock files in /var/mail, where my inbox is stored. (Usually Dovecot's imap-login process would start imap as root, and then it would switch itself to the group set in mail_privileged_group when necessary.) So I get a ton of messages like this:
...resulting in “Mutt: Mailbox readonly” warnings every time I try to delete something.
It would be possible to change the permissions of /var/mail to 01777 (sticky, read/write/execute for everyone), but this feels a little insecure compared to the default 02775 root:mail.
The solution is to give /usr/lib/dovecot/imap access to the mail group using the setgid bit:
(Update: The latest version of freetype2 has a quite good TrueType rendering engine with ClearType support, which makes such configuration no longer necessary... assuming your distro enables that feature, which I have to do manually in Arch. The config file has been moved, also. – 2014-08-22)
Calibri, one of Microsoft's ClearType fonts, has a few sets of bitmaps embedded into it, to make it look better when font smoothing is off. Which results in Calibri looking just plain ugly in X11/Freetype when you enable hinting.
To disable embedded bitmaps, put this into your ~/.config/fontconfig/fonts.conf: