"Unable to send e-mail" Error in drupal 7 Just now I migrated my website to server machine. I noticed that website is not able to send any email. It is showing "Unable to send e-mail" error.

Below is the screenshot of the error-


I can see some directory permissions error in status report at admin/reports/status. Are these related to each other?
It's very likely that your new server does not allow mail to be sent from the web service.   This could be because it blocks the SMTP port, or because it doesn't allow PHP to use mail().  You should be able to contact their tech support to ask.  If not,  you can try uploading your own PHP script that uses the mail() function and see what errors it gives you.

IMO, this is a good thing... web servers shouldn't be sending emails for a variety of reasons.

I would recommend using something like this:  https://drupal.org/project/smtp

It will let you send email through a real email account, of course you'll have to make sure there's not a block on the port it uses.