Could not instantiate mail function

[joro2002]

Due to my host company, I'm allowed to use only PHP mail transport method. But i found out that whit that method zencart doesnt send e-mails. For example when i've tried to change order status and send email to customer, error message appears:

Could not instantiate mail function

After some digging, i found out that on my server the problem was in email message SUBJECT length.I've counted that there is limitation of 36 symbols when zencart sends "changed status" email, and 31 symbols when customer makes new order.

Actually on my server there is limitations to all emails subject length (for instance admin notification for pending reviews), but i doest count them.

So bassicly, on my server, using PHP transport method, and my zencart doesnt send emails, I needed to change EMAIL SUBJECT length for all types of emails.

For example my zencart doesnt sends email to my customers, when they make new order. So I must change subject length of mail which is send when new order is made.

includes/languages/english/checkuot_process.php

find that line:
EMAIL_TEXT_SUBJECT
and I must change it to something less then 31 symbols. For example:
define('EMAIL_TEXT_SUBJECT', 'New order');

That is for new orders. Since I am getting:

Could not instantiate mail function

I must change:
admin/includes/languages/english/order.php

Find this:
EMAIL_TEXT_SUBJECT

and change it to something less than 36 symbols:
For example:
define('EMAIL_TEXT_SUBJECT', 'Status changed');

There is plenty more emails sended from zencart, so must make sure that theirs subject length is appropriate for PHP mail transport method. May wish to change length of this variables:

checkout_process.php:define('EMAIL_TEXT_SUBJECT', '');
checkout_process.php:define('EMAIL_ORDER_NUMBER_SUBJECT', ' : ');
contact_us.php:define('EMAIL_SUBJECT', '');
create_account.php:define('EMAIL_SUBJECT', '');
email_extras.php: define('SEND_EXTRA_CREATE_ACCOUNT_EMAILS_TO_SUBJECT','');
email_extras.php: define('SEND_EXTRA_NEW_ORDERS_EMAILS_TO_SUBJECT','');
email_extras.php: define('SEND_EXTRA_CC_EMAILS_TO_SUBJECT','[EXTRA CC ORDER info] #');
email_extras.php: define('EMAIL_TEXT_SUBJECT_LOWSTOCK',');
gv_send.php:define('EMAIL_SUBJECT', 'Message from ' . STORE_NAME);
hints_add.php:define('EMAIL_SUBJECT', '');
password_forgotten.php:define('EMAIL_PASSWORD_REMINDER_SUBJECT', STORE_NAME . ' - Нова парола');
product_reviews_write.php:define('EMAIL_REVIEW_PENDING_SUBJECT','');
tell_a_friend.php:define('EMAIL_TEXT_SUBJECT', 'Your friend %s has recommended this great product from %s');