How to Compress Image Before Sending Email in Outlook? [4 Ways]

Everybody knows if you try to send an attachment in Outlook, and the size of the attachment is more than the allowed limit of 20 megabytes (MB).

If you are sending multiple images in a single email message in Outlook as an attachment, and it looks like the size of the images is large, you have an option to compress the image attachments.

In this article, you will learn a couple of methods “How to Resize an Image in Outlook Email?

How to Reduce the Size of Attached Pictures?

If you’re sending large files, the best way to do it is to upload them to an external resource like Dropbox or Google Drive and then share the link. Even in Outlook, you can try to reduce the size of picture attachments.

Let’s begin and understand the ways, you can easily Compress Your Image Before Sending an Email in Outlook, some of the technics are very common and all of you are aware of them, but some of them are really interesting and everybody should know of them.

Resize Large Images when I send this message

This inbuilt feature resizes large images when you send the email message in Outlook.

Step 1: – Open Outlook, Create a new message.

Step 2: – Add a picture to the message as an attachment

Step 3: – Click on the File Tab, under info image attachment Some recipients may not receive this message because of image attachments. Resizing large images may help the message get delivered. Resized images will be a maximum of 1024×768 pixels. is available, by default “Do not resize an image is selected.

Step 4: – Select Resize large images when I send this message.

Step 5:- Final Step is to go back by clicking the back button on the top left corner of the screen, complete your message, and send the message, all your attachments will be resized automatically.

Previously the size of all the attachments and the size after all of them are compressed is apparent:

Sr. No.Size of Attachment before ResizeSize of Attachment after Resize
1445 KB41 KB
2180 KB54 KB
3539 KB54 KB
Table: reveal the outcome before and after resizing the images

Compress Images Before Sending Emails by Context Menu

In most cases, you create a new email message and then click attach to add pictures to your email, in this method you can use the context menu.

First, select your images and use the context menu to reduce the size of images >> Right click to display the context menu >> Send to >> Mail Recipient

Attach Files dialog box appears, select the size you need from the drop-down list of Picture sizes. The original size mentioned is the actual size of the image, you can select smaller or small to reduce the size.

Click attach, then all resized images are added in a new message window in Outlook as attachments, the image’s names are also added in the message body, which you can remove or edit, and you can compose your email accordingly.

This feature is really effective you can check the result by yourself,

In the above example I have taken five images which in totality have 1.86 MB size, but after opting for small: 800 X 600 the size of all the images compressed to 703 KB, which is reduced by more than 36%. If I go with the smallest 640 X 480 the size is reduced to 450 KB, which is 58%.

Compress Images Online.

There are tons of Free online platforms available that help you to reduce the image size according to your requirement.

One of them is tinypng, which I personally use to reduce the size of the image. once your image is reduced you can easily attach the image file and send it to your recipient.

Compress Images using VBA

Outlook macros are also designed to solve this problem for Outlook users. You can attach all the images to your Outlook email, and you can compress and convert the images into ZIP files using the VBA code.

  • Open Outlook >> Compose your email and attach all the images to it.
  • Then, press ‘Alt + F11’ to trigger the Outlook VBA editor.
  • Download the below VBA code, copy, and paste it to the Visual editor page.
Sub ZipImageAttachments()
    Dim objMail As Outlook.MailItem
    Dim objAttachments As Outlook.Attachments
    Dim objAttachment As Outlook.Attachment
    Dim i As Long
    Dim objFileSystem As Object
    Dim objShell As Object
    Dim varTempFolder As Variant
    Dim varZipFile As Variant
    Set objFileSystem = CreateObject("Scripting.FileSystemObject")
    varTempFolder = objFileSystem.GetSpecialFolder(2).Path & "\Temp " & Format(Now, "dd-mm-yyyy- hh-mm-ss-")
    MkDir (varTempFolder)
    varTempFolder = varTempFolder & "\"
    Set objMail = Outlook.Application.ActiveInspector.currentItem
    Set objAttachments = objMail.Attachments
    For i = objAttachments.Count To 1 Step -1
        Set objAttachment = objAttachments(i)
        If IsEmbedded(objAttachment) = False Then
           Select Case LCase(objFileSystem.GetExtensionName(objAttachment.FileName))
                  Case "jpg", "jpeg", "png", "bmp", "gif"
                        objAttachment.SaveAsFile (varTempFolder & objAttachment.FileName)
           End Select
        End If
    varZipFile = objFileSystem.GetSpecialFolder(2).Path & "\"
    Open varZipFile For Output As #1
    Print #1, Chr$(80) & Chr$(75) & Chr$(5) & Chr$(6) & String(18, 0)
    Close #1
    Set objShell = CreateObject("Shell.Application")
    objShell.NameSpace(varZipFile).CopyHere objShell.NameSpace(varTempFolder).Items

    On Error Resume Next
    Do Until objShell.NameSpace(varZipFile).Items.Count = objShell.NameSpace(varTempFolder).Items.Count
       Application.Wait (Now + TimeValue("0:00:01"))
    On Error GoTo 0

    objMail.Attachments.Add varZipFile
End Sub

Function IsEmbedded(objCurrentAttachment As Outlook.Attachment) As Boolean
    Dim objPropertyAccessor As Outlook.PropertyAccessor
    Dim strProperty As String
    Set objPropertyAccessor = objCurrentAttachment.PropertyAccessor
    strProperty = objPropertyAccessor.GetProperty("")
    If InStr(1, strProperty, "@") > 0 Then
       IsEmbedded = True
       IsEmbedded = False
    End If
End Function
  • Hit F5 or Run icon to activate the Macros.
  • Close Microsoft Visual Window, and you will observe that all your image attachments are converted into zip/rar files.


In conclusion, although sending large images via attachment is discouraged, many users do this regularly.

When users send large images, Outlook limits the size of the attachment based on the file size.

If a user sends a large image, Outlook will compress the image to reduce its file size. This will reduce the image quality and file size.

You will get four ways to compress the image attachment before sending an email from Outlook.

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