1. Failed to login either without further message or some FileVault error
$HOME may still be mounted. see mount, then unmount your home dir, e.g.
hdiutil unmount /Users/test
See also Best Practices for Using FileVault.
2. Resolve intranet hostnames via VPN
Suppose foo.bar is the internal domain name on the other side of a VPN connection. And hosts under foo.bar can not be resolved by the default name server. Then, without changing the DNS configuration globally, there is a rather elegant solution within the mac's name resolver:
$ cat /etc/resolver/foo.barSee $ man 5 resolver for further details.
3. GPGMail Key pre-selection
GPGMail, the one must-have Plugin for Mail.app, selects keys for encryption automatically, based on the recipient's email address. If either this email address is not listed under the appropriate key (see gpg --list-keys), or the receiver is a mailing list with several subscribers, the automatic key preselection fails.
That is, unless groups have been created in ~/.gnupg/gpg.conf like so:
group email@example.com = 0x12345678 0xABCDEF12 0x00000001
See also: $ info gpg