Microsoft Outlook supports not only attaching files from your hard disk, but also inserting Outlook items, such as emails, meeting invitations, appointments, contacts, etc. as attachments in an email.

1. In the Mail view, click Home > New Email to create a new email.

2. In the new Message window, click Insert > Outlook Item. See screenshot:

3. In the opening Insert Item dialog box, please see screenshot below:

(1) In the Look in section, click to highlight the folder whose items you will insert as attachments. For attaching emails, please select a mail folder; for attaching meeting invitations, please select the Calendar.
(2) In the Items section, select one or multiple items you will insert as attachments;
(3) In the Insert as section, check the Attachment option;
(4) Click the OK button.

4. Now the selected Outlook items are inserted as attachments in the new email as below screenshot shown. Please compose this email and send it.

Note: If you check the Text only option in the Insert as section, the selected Outlook item will be inserted into the message body as below screenshot shown:

Automatically add text,current date/time to subject or signature in Outlook

Provided by Kutools for Outlook.

We can quickly add one or multiple emails as attachments in a new email with the Forward as Attachment feature in Outlook.

1. In the Mail view, open the mail folder whose emails you will attach as attachments, and then select emails in the mail list.
Note: Holding the Ctrl key, you can select multiple nonadjacent emails with clicking them one by one; holding the Shift key, you can select multiple adjacent emails with clicking the first one and the last one.

2. Click Home > More > Forward as Attachment.

3. Now all selected emails are inserted as attachments into a new email, please compose this email and send it.

Attach recent documents/items in an email in Outlook