Email with an attachment bounces back saying data size exceeds limits

You are sending a mail to someone, and that mail is bouncing back saying size limit exceeded?

Nothing you can do about that, it's a setting on the receiving end.

If this is a mail being sent to you that is bouncing, what are you running for your incoming mail server?

No.  That is not the problem.  I am sending an email with an attachment.  The email bounces back to me saying the data size exceeds the limits.

The following recipient(s) cannot be reached:

      'jchennault@aol.com' on 10/20/2011 7:37 PM
            552 5.2.3 DATA size exceeds maximum permitted

From the limited amount of info provided, that limit is set by the receiving server, nothing can be changed on your end aside from making the attachment smaller.  The error could however be from an upstream mail relay that is still on the sending side.  Have to keep guessing about that however since only those 2 lines were pasted from the bounce message.

What is the maximum e-mail message size that AOL Members can accept from the Internet?

    The largest piece of e-mail that an AOL member can accept from or send to the Internet is 25 megabytes. This includes the message text, headers and the attachment combined. This size cannot be configured by the Member, or adjusted by the Postmaster team.

http://postmaster.aol.com/Postmaster.FAQ.php

What is the size of the attachment you are trying to send mtcbslm? Also, what type of file is it?

Although this Experts-Exchange question is over 2 years old it may be still be relevant to your situation:
https://www.experts-exchange.com/questions/24328007/exchange-2007-wont-allow-messages-over-9mb.html

Since the problem is with sending an attachment over a certain size, and it's enforced either by your email system or the recipient's, you can't do anything about it. You need to go a different route, and the solution is to use a large file sending service. I personally use YouSendIt (www.yousendit.com), which allows you to send files of up to 50 MB for free (2 GB if you pay for their $50/year Pro service). The way it works is that you upload the file to their server, and they send the recipient an email with a web link to download the file. This is also useful if you have a file that is considered dangerous, and the recipient's email system blocks it (such as an executable file, for fear of viruses).

There are lots of similar services; do a Google search for "send large files". One reason I prefer YouSendIt is that I don't have to go to their website; they have a small app that integrates into the right-click menu of My Computer, so you can click on a file and send it. But their maximum file size for the free version is smaller than some of the others.

BTW, 50 points for this question? Why so little? If you're a premium service member, it's not like the points cost you anything...