Unfortunately photos, typically in jpg format are one of those files that I mentioned above which are not too compressible much beyond their present size. What you will likely need to do is re-size the images in order to make them smaller.
If you have installed a default email client like Outlook you can typically select multiple photos and then choose "Send To" -> "mail recipient" and then you should be given an opportunity to make them smaller to keep the overall file size underneath any restriction set by your mail host.