when is send mail it show an internal server error

[dambaru]

when ever i send a mail it shows me an "500 - Internal server error.There is a problem with the resource you are looking for, and it cannot be displayed."plz its solution

[Luuk]

This problem would be easier to solve if you showed your code.
There's no need to put existing email addresses in it,

The error 500 can also be a (mis-)configured mailserver.