No mail() from my server, sendmail can't install

Hi there, I have sometrouble w/ sending mail from my server, I have an Ubuntu 14.* and last VestaCP, so, it can’t emailing :C I tryed to install php-mail and sendmail, but somewhat crashed:

root@digitalsharks:~# apt-get install php-mail
Reading package lists... Done
Building dependency tree
Reading state information... Done
php-mail is already the newest version.
php-mail set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 18 not upgraded.
root@digitalsharks:~# apt-get install sendmail
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 sendmail : Depends: sendmail-bin but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Sorry, guys. I’m amauter in linux C: