[imp] imp_expand_fromaddress

[Stephen A. Cochran]

In setting this up to auto-generate the from address (our IMAP server 
allows authentication via usernames with spaces and nicknames, so we 
need to make sure the correct email gets in outgoing messages), I've 
noticed that a lookup is done every time a new compose window is opened.

Since this adds an unnecessary load onto a directory server, I've 
modified IMP.php and conf.php with another hook function which stores 
the users's email address in $imp. Right after vinfo is called in 
IMP.php, it will also call the ['hook']['email'] function.

I was figuring I'd offer this back to the project if anyone else wants 
it, but then got thinking that this might not 'fit' with the multiple 
identities model you have, since it forces one from email for every 
user. This works fine in our setup, since we have multiple idents 
turned off anyway.

Thoughts?

Steve Cochran