Compose mail

[maagheli]

I want to configure IMP for my users. but i have this following
problems:

1- I cannot send message.
      When ever i click compose, fill fields and click send message,
doesn't
send my mail (return to compose screen) . also about attach. (NOTE: My
web
server and mail server are separate)

2- When i select POP3 method before login, i connect to server port 110,

but it doesn't work really (it work like IMAP).

I have:
    imp-2.2.3-1.1
    horde-1.2.3-1.1
    horde-mysql-1.3.3-1.1
    phplib-7.2-1
    php-mysql-3.0.18-6.2horde1
    php-3.0.18-1.6x
    php-ldap-3.0.18-1.6.x

If you can, help me please.
Thanks in advance