When you forward an email with attachments in Outlook, the attachments will be attached in the forwarded message automatically. However, when replying this email, attachments won't show in the replying message until you copy them from original email and then paste into the replying message manually. But Kutools for Outlook's Reply All with Attachment utility can help you keep attachments when replying all in Outlook easily.

For example, you want to reply to the sender and all other recipients of an email with a series of attachments in Outlook, you can keep all attachments when replying all as follow.

1. In the Mail view, select the email with attachments you want to reply all.

2. Apply the Reply All with Attachment utility with clicking Kutools > Reply with Attachment > Reply All with Attachment.

Then you will see all original attachments are listing in the Attached box in the reading pane. See screenshot:

3. Compose the replying message, and click Send button.

If you view an email in Message window, you can also apply this utility with clicking Kutools > Reply All with Attachment. See screenshot: