[Resolved] Can't send mail to new users - please help

I love MODx but I’m having some problems with my install.
The latest problem is: when creating a new user, I get an error when sending them their (generated) password. The alert I’m receiving is: "Error while sending mail to". Apart from that, the new user is being created, except off course they can’t login, because they never received their password.
I’ve checked with the provider whether php Safe Mode is enabled, but this isn’t the case. Any ideas? Please?

Edit: server info:
PHP: 4.4.4-0.dotdeb.1
MySQL: 4.1.15
Server: Apache/1.3.33 (Debian GNU/Linux)

Have you double-checked that your send-from addresses are set correctly?

Hmmm.. what do you mean by ’correctly’? I have found only one place where I can set a ’from’ address: administration > system configuration > e-mailaddress. I have used my own address, which is not in the same domain as the site itself. I don’t think any e-mailadresses have been configured for this domain. Could this be the problem?
How can I tell what the from-address should be?
Oh- and thanks, of course

Some providers will limit you to sending from email addresses that are not set up on the box, so yes that *could* be the problem.

Do any other mail scripts work?

Oh, and can you please confirm what version of MODx you are using, and confirm that you are talking about the facility in the Manager for adding users?

Other mailscripts do work. I just put up a testpage (outside of MODx) with a form I made myself and it works. This form takes the user input and puts it inside an email that is being sent to a certain (hardcoded) address. For ’sender’ I used the same address as in MODx.
I’m using version 0.9.2.1 and yes, we are talking about the manager: Users > Manage Users > New User

Also, I’m not sure if this is relevant, but in my phpinfo file it says:

It may be that the internal script is not setting the return-path (the -f switch) properly and trying to send the email as [email protected]. I’ll have to look into this, but that’s my first inclination.

Do you mean a MODx internal script, and is there something I can do to solve this problem? Because I’d really like to solve it...

So, I managed to solve the problem myself
I’m going to post here what I did in order to solve it, in case someone else gets the same problem in the future.
In the file manager > processors > save_user.processor.php I changed this line (line 446):

into this:

In other words: I removed the last part.
Perhaps one of the coders can tell me: did I do the right thing, or have I somehow made the script less secure or something? Because I’m not exactly a php expert...

Oh I think I also fixed a tiny bug in the line right below, which used to be:

I changed ’$mailto’ into ’$email’, this way you get a proper error message with the emailaddress in it

Apparently, your host does not allow setting the return-path switch (the -f part which you removed), which is unfortunate, since that means that all mail you send will have whatever return-path the host provider has configured for you.

I see. Oh well, we can live with that. Thanks for your help!