You might try this. RIGHT CLICK on jpg, select SEND TO. MAIL RECIPIENT, select Picture size (maybe smaller) & click ATTACH. Delete whatever text is present in the email, if you want.
Email recipient could probably zoom the picture to view larger display. I tried this with Thunderbird, attached jpg (smaller) was 32% of original file size. I opened attached jpg with Windows Photo Viewer, which easily increased display size of photo for viewing.
Dell installed 'Adobe Photoshop Elements 9' free on my Dell in 2012. Photoshop can reduce jpg file size while retaining the original photo dimensions. Open photo with Photoshop, EDIT, SAVE FOR WEB, select size (low, med, high, very high, maximum), click OK, and SAVE file. On LOW, looked like my test jpg was maybe 5% of original file size, and I couldn't tell any quality difference.