Some emails couldn't get the test confirm letter in 1.5.4

[wjq588jk]

Hello,

I have build a website use ps 1.5.4,when I test the email configuration and find some emails couldn't get the test letter:This is a test message. Your server is now configured to send email. such as [email protected] , [email protected] , [email protected] (I have check the inbox and spam box ) ,and so on . And some emails can get the confirm letter. I use the prestashop default PHP mail() function.

So anyone who knows the reason,please?

Thanks very much.