[mimp] send mail

[ml@b4rt.widge.to]

hi, i've a big problem with mimp.
I've try configuring horde framework with sendmail
or with smtp server but it's the same.
Imp sendmail but mimp don't do it!
I've enable logging and i obtain: 

Feb  3 08:43:21 localhost HORDE[13985]: [mimp] 10.10.1.10 Message sent to 
xxx at xxx.it from xxx [on line 421 of "/usr/share/horde3/mimp/compose.php"] 

but the mail is not send and my mail.log
don't say nothing.
it like that mimp don't try to send out email.
I'm using the 1.0-beta version of mimp and
3.0.4-4sarge2 version of horde.
my system is a debian sarge. 

thank you a lot 

Denis