mailing by mail() does not work however sendmail - works

[Evadik]

Hi,

Mantis had been failed to send emails when it was configured to send via mail() function.
# select the method to mail by:
# 0 - mail()
# 1 - sendmail
# 2 - SMTP
$g_phpMailer_method = 0;

After chaning g_phpMailer_method = 1 - to use sendmail - mail is sent normally.

Other php software installed on the same server sends using mail() function without any problems.

Please explain what is the reason of the problem.

Thanks