What mail server are you using? Your ISP's? Or somebody else's?
The mail message is treated as relayed mail, so Yahoo is rejecting it.
A mail server has to be configured to allow relaying from the machine
that is running your Perl script, and the recipient's mail server has
to be configured to accept mail from that mail server.
Another possibility is that your ISPs mail server is not
configured and allows relaying from spammers, so it's on a list of mail
servers that Yahoo blocks. See ORBZ
for more information on this.
This has nothing to do with the From: or Sender: headers.
Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
Want more info? How to link or
or How to display code and escape characters
are good places to start.