[imp] mailbox display problem / indentity issue

[Liam Hoekenga]

It appears that if any of your identities only has an "@" in the From field, the
"From" column in the mailbox view displays the "To: user@example.com" header
instead of the actual "From" field.  It works properly if the identity's "From"
field is completely empty, or if it contains a proper email address.

I've been able to replicate this in the 3.1 and HEAD releases.  PHP 4.2.2,
Apache 1.3.26, Solaris 8.

I know people aren't likely to configure their identities this way, but, we had
a user report this.. so there's at least one person who set their account up
strangely.

Liam