lorid, you will have to copy your picture to a different format to reduce the file size.
I use MS Digital Image Standard and this is the procedure I use.
First, find and open the picture you want to upload or attach, then click on File, go down to Save a Copy and then click on For E-mail or Web .
Then select a picture size from the drop down window...... such as Small Web View or Medium Web View
Then click Save As ........ and you have thus created a "copy" with a reduced KByte file size suitable for uploading.
You can also "crop" the picture so only the "object" is in view ...... and that also decreases the KBytes file size.