the first error you are getting is the headers already sent error. this error is caused by space between php tags. it is reporting the error at line 4. most likely there is a blank space at the end of line 3:
see the following page for details:
most of the other errors are related to the first one except fro this error:
open_basedir restriction in effect. File(/usr/bin/pearMail.php) is not within the allowed path(s): (.:/php/includes:/usr/local/pem/vhosts/126152)
1) it looks like you have entered the path to pear as:
you need to include a trailing /
2) it looks like that may not be the correct path to use as the error is reporting that path as being blocked by the open_basedir restriction.
you can try leaving the path to pear blank, that will cause the script to use the path that is defined in the php.ini file, if that does not work, you will need to contact the host to find the correct path to use.