[imp] imp_expand_fromaddress with imp 4

[THEVENIN Valerie]

Hello

With imp 3.2.7  we were using the function imp_expand_fromaddress in the 
conf.php ( $conf['hooks']['from'] = 'imp_expand_fromaddress';) in order to 
send message with the mail adress stored in our ldap server (and not by 
default as login at domain).

We've migrated to imp 4 and we are not able to produce the same behaviour.

Does anyone know how to do it (without asking users to modify their 
identity in their option)

Thanks

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Valerie Thevenin
Université de Technologie de Troyes
E-Mail : Valerie.Thevenin at utt.fr