Problem sending email from a wordpress blog...

I'm reposting this here because I think I am more likely to get some help with it here. Ok here's the problem:

I'm using DekoBoko plugin to create contact form at my blog. The form works perfectly (including recaptcha etc) - the only problem is that when I fill in all information and press submit, I get this error:

I've taken a look into DekoBoko plugin file and I found out that it is using wp_mail() function to send the email instead of ordinary php mail(). I've also tried replacing wp_mail() with mail() but I get the same error, so I suppose there's some problem with my mail settings at the VPS?

I am trying to send emails through this form to email account which is on my VPS and is functional so there's shouldn't problem.

I'm using Wordpress 2.5.1.

Here is the contact form: http://seowebtips.com/contact/

Please take a look at it and please suggest me what might be a problem. Thanks very much.

 

Fortunately, I have solved the issue

 

What was it ? We want to know.

 

I'm not sure exactly what was the problem but it disappeared once I rebooted my server - probably PHP interpreter wasn't running properly in the background or some corrupted file in RAM memory.