How to Resize Images in Outlook Attachments Before Sending Them

Cloud solutions like Dropbox and OneDrive are a handy way of sharing images with others, but there may be times when you need to send them over to your clients via email.  Since most ISPs have a file transfer limit, and email recipients have limited mail storage, if your email exceeds these limits, it will be returned as undelivered.

In simple words, your email message will bounce back to you. Therefore, it is always better to optimize the size of your messages to ensure that they stay within the maximum message size limits that are common to most email accounts.

Remember that most email messages increase in size during transit. In fact they are said to increase by about one-third of their original size during the encoding process. So if you have an email message with attachments and graphics amounting to about 9MB and your ISP allows for a maximum size of up to 10MB, your message will increase beyond the acceptable limit and bounce back.

Don’t forget that apart from the email bouncing back, your storage capacity will also be affected as a copy of the email will be sitting in your Sent Items folder, taking up unwanted extra space.

So how can you resize large images and attachments in Outlook without wasting time and affecting the quality of your original? Let's find out.

How to Resize Images in Outlook Attachments

When you attach pictures to an Outlook message, you can resize the large images to a maximum resolution of 1024x768. This is usually done on a per message basis. However, if you embed the picture in the body of the message, you cannot resize the image in  Outlook. It has to be resized before embedding.

1. Compose a new email message.

2. On the Insert tab, in the Include group, click Attach File. (Alternately, you can drag an image from File Explorer and drop it below the Subject field.)

3. In the message window, select the File tab.

4. In the Info tab, in the Image Attachments section, select Resize large images when I send this message.

5. Click the Message tab to get back to your email.

6. Complete your message and click Send.

For the purpose of this tutorial, I attached 2 images of sizes 2MB and 688 KB. They were automatically resized and sent to the recipient at 30KB and 68 KB respectively.

How to Resize Images in Outlook Using Attach Files Option

If you are working in File Explorer and choose to send a few images via Outlook to your client, you can do it using the Send to command. Here’s how:

1. In File Explorer, select the images you want to send via Outlook.

2. Right-click the images and from the contextual menu, select Send to->Mail recipient.

3. The Attach Files dialog box is displayed. From the Picture size dropdown menu, select an appropriate size. The dialog box will display the total estimated size of the option you selected.

4. Click Attach.

In my example, the file size reduced from 2.89MB to 180 KB.

Assuming Outlook is your default email client, a new email message will be opened and the images automatically resized and attached. You can then compose your email and send it to your recipient.

Resizing Images Embedded in the Message Body

You cannot resize images in the body of a message but can compress it. However do this only if you don’t mind compromising on the quality of the image.

To compress an image in the body of an email:

1. Embed the image in the body of the message.

2. Click the images to activate the Picture Tools contextual tab.

3. Click the picture or pictures that you want to change the resolution for.

4. In the Picture Tools Format tab, in the Adjust group, click Compress Pictures.

5. In the Compress Pictures dialog box, select a desired resolution and click OK. ( Make sure that Apply only to this picture check box is selected.)

One downside to this is that after compression, the picture may look different from the original.

So the next time you plan to send a large image or images via Outlook, make sure you optimize the images using the steps outlined in this tutorial.