photos get stuck in outbox ???

Your question is too vague. Thousands (millions) of emails containing photos are sent every day, so it's likely something to do with your particular setup, or something in this particular email, that's causing the problem.

Also, this post is in the Mac OS X Server 10.5.x forum, so are you asking from a mail server standpoint? or from a client application standpoint?

If on the client side, what do you see? does the message sit forever in your outbox? or does it go, but never appear on the recipient's end?

Without more data, the most likely scenarios are that the image is too large - or, more precisely, the image extends the size of the email message beyond what the server is capable of supporting (or at least is configured/constrained to).

Unfortunately it's not easy to see/predict the size of an outgoing message in Mail.app (if that's the mail client you're using), so you may need to look at the server-side logs for any hints. You could also try resizing the image (sending a smaller/lower resolution image) to see if that works, increasing the size incrementally until you hit the limit.

There are also many other reasons, typically server-side) that could block a message - most notably spam filters that block the message based on some content. That will be harder to get around if you don't control the server.

In any case, more data is needed if you need a more complete answer.