Sharepoint Alert cannot send email

[xxxdc]

Hi all,
I have this error when i tried to add new user.
"The user or users have been added successfully, but there was an error in sending the e-mail message. The server may not be set up correctly to send e-mail. To verify that e-mail is configured correctly, contact your server administrator."
I already check the SPSNOtification.exe, is running well, also no problem with smtp server.(i use separate server,one for sharepont, one for mail server.)
can anybody give me advice how to solve this problem.
Note : I see in log, one of log say my smtp server no response, and previusely my alert is working well.

xxxdc

[Jay Mueller]

Can you ping the SMTP server from the Front-End Webserver?

[itman]

Hi
The problem, as I see it. lies in when you adding a new user, you alert setting has no problem. My experience tells me that adding a new user need resetting all the alert.
So if you want some add some one that heritage the setting you need group the people, but so far I just got this clue, I have not got any idea whether this can be done yet.
I recommend you to install an add-on called Alert reminder boost.
It can provide you several triggering conditions of email. you can get it from www.sharepointboost.com
Perhaps I take this too easy.
Hope this can help you.