[horde] "sendmail returned error code 127"

[Spyros Tsiolis]

Any ideas ?

horde-webmail edition v1.2.5 and trying to use XMail for mstp/pop3
googled up a couple of dozen pages and the general idea is to find
sendmail and replace it with "SMTP" (they say).

However, I don't know where to look. Or the places I look at 
("/var/www/horde/config/horde.php" / "/var/www/horde/imp/config/conf.php")
, there's nothing there.

Any help would be nice,

Thank you list,

s.