It has been 2.5 years since the last SquirrelMail release. In this
time, there have been many fixes added to the source tree, including
the PHP 5.4 and 5.5 fixes, requests for which have become the bane
of my maintainer existence.
The SM team is hard at work on the next version, but at this time it
is unclear whether the next version will ever see a full release.
As a result, this port will begin following hand-picked SVN snapshots.
So, the port officially accepts PHP 5.4 and 5.5, though if you
encounter weird errors please DTRT and report it to the SM developers
and then downgrade your PHP to 5.3.
The other major thing here is that the default location for user
preferences and attachments is being changed. Previously we used
/var/spool/squirrelmail which is really not in-line with FreeBSD's
hier(7). Now we use paths under $PREFIX, respectively
$PREFIX/www/squirrelmail/data and .../attach.
You can either copy /var/spool/squirrelmail/pref/* into
$PREFIX/www/squirrelmail/data, and /var/.../attach/* into
$PREFIX/.../attach, and then run $PREFIX/www/squirrelmail/configure,
or you can do nothing in which case that's totally fine too and
your installation won't break or anything.
Note that best practice, as recommended by the SM installation notes
and common sense, would suggest moving your user data files
to someplace outside of the $PREFIX/www/squirrelmail.