Problem with qmail and HtmlMimeMail 2.5.1

[troni]

Hi folks,

I'd like to send an email via PHP-Script and HtmlMimeMail but a problem occurs and the email will not be sent.

I receive an error-messages like:

Warning: set_time_limit(): Cannot set time limit in safe mode in
/usr/share/htmlMimeMail-2.5.1/RFC822.php on line 159

Turning off the Safe_mode brings no success.

In my maillog is the following entry:

Jun 25 16:05:17 qmail-queue: drweb-qmail[16980]:
possible qmail-smtpd exited by timeout, reset connection or with "See
http://pobox.com/~djb/docs/smtplf.html."

The path to qmail in php.ini is

/var/qmail/bin/qmail-inject

and I tried also

/usr/sbin/sendmail

I'm using the standard installation of Plesk 7.5.3.

It would be great, if anybody can help me or give me a hint.

Thx a lot,

Ralph