escaping quotes in mail() message

I'm having a problem escaping double quotes in email messages sent with mail(). The message is built as a string and assigned to a variable and the variable name is passed to the mail function. The double quotes appear correctly in a simple test like this: $message = "This message uses 'single' and \"double\" quotes."; mail($sendto, $subject, $message, $headers); But if $message is built in another part of the script and passed as a hidden input of a form, the email arrives with the message truncated at the first double quote encountered. If I do a str_replace() on $message to escape double quotes, the email shows the escaping backslash but is still truncated at the double quote! I've got magic_quotes on, but I think I'm keeping up with stripslashes because single quotes are showing up correctly. Can anyone please advise? -- Lowell Allen