Prostfix cant send mails

[t_ras]

using kubuntu 9.04 on AMD 64,working with ISPconfig panel.
I have mail configured with Postfix. It works fine from the server (and of course through squirrelmail installed in it), but I cant send from other computers.
Any ideas?

THanks

[ruuden]

After you try to send mail check your mail log with this command:

tail -20 /var/log/mail.log

this command will show the last 20 entries in your mail log

[t_ras]

Thanks for th tip. it seems it was an authentication issue. I tried specific type. when left for Outlook to choose it worked fine.