How do I send multiple pictures in email ?

20 pictures in one email?  Be aware of the total size of this email and get it as small as possible or you might have some frustrated clients.  Images right off the camera often have a large file size.  Before emailing images, you need to determine if your recipients really need the images at full resolution or would a smaller sized image (dimension and file-size) will suffice. Sending multiple images in a single email is tricky and there are a few ways to do it.  One way is to compress them down to about 100KB each, put them into a descriptively named folder, then zip (compress) the folder.  This will create a zipped file that will weigh in between 2 and 3MB which is an acceptable attachment file-size these days.  Next, attach the zip file to an email.  In my opinion, this is the most professional way to send multiple images. All you need is your camera and a PC.  Skills needed will be knowing how to copy/paste files, renaming files/folders, resizing/compressing/resaving images using an image editor, creating folders, Windows navigation, zipping files/folders, and creating emails with attachments. My favorite basic image editor/viewer is Irfanview.  It's easy to understand and it's free.  Until you get this image thing down, always work with copies of images and not originals.  Open the image up with Irfanview, hit File>Save As.  Choose jpg as the file type and move the compression slider to about 70%.  Give the picture a descriptive name and click Save.  Hopefully you have Windows navigation down because you will need to determine where to save the "new" compressed image, then go to the saved image and check its properties to see if you got it down to 100-150KB in file-size. Create a new folder, name it, put the "new" compressed images into the folder, right-click on the folder, select "Send To", from the pop-out select "Compressed (zipped) Folder".  This newly created file will be automatically placed in teh same directory as the original folder -it looks like a folder with zipper on it.  Think of it as a container.  This is what you attach to the email.  Before you attach and send it, right-click on it and check the Properties for the file size.  Again, 2-3 MB is an acceptable size these days for an attachment. There's more to basic image editing than that.  If you want to make the images dimensionally smaller than the super-duper-extra-large-mega-pixel size that the originals probably are (if they came from a camera), use Ifranview to change the dimensions.  Open each image with Irfanview.  At the top, click Image>Resize/Resample, and choose something usable like 1024x768 or 800x600.  Decreasing the image dimensions will make it easy to get our 100KB goal, so if you are going to to both, decrease the dimensions first then compress to 70-75%. Remember to use jpg as the "Save As" file type since jpg is a universal image file type. That was the Reader's Digest version of Imaging and Emailing 101.  Good luck!

See the LOOOONG post about using a compression utility to create a .zip file. Nutshell: Use reasonably sized images (.jpg @ ~150KB each), put images in a descriptively-named folder, right-click and choose Send-To>Compressed Folder. This creates a zipped file which contains your photos and this is what you attach to your email.

by reading through the comments you can see that the only real answer is: it depends
It depends on the operating system you are using, and the mail-client.

Please help me. Thanks.

JUST left clicking would not make anything disappear. You have probably either deleted it or moved it. Check in your recycle bin. if it's not there, do a full search and it should turn up.