The articles listed below contain VBA code samples. Additional code samples are listed at Developer Samples

Use Word Macro to Apply Formatting to Email
How to use a VBA macro recorded in Microsoft Word to apply formatting in an Outlook email message.

How to change the From field on incoming messages
How to use Redemption to change the sender's name field on messages.

Save Messages as *.DOC or *.DOCX File Type
If you want to save messages in a universal format and want the attachments stay with the document, you need to convert the message to RTF format then save the message in *.doc format. . While you can do this in Outlook, it takes several steps. Using VBA to save messages to your hard drive in *.doc format takes just seconds.
Use VBA to move messages with attachments
Use a run a script rule or an ItemAdd macro to look for messages with attachments. When the attachment is a specific file type, do something with the message.

Backup Calendar, Contacts, Tasks in an IMAP data file
Use a macro to copy appointments, contacts, tasks, and notes to a *.pst file before removing an IMAP account from Outlook 2013.

Run a script rule: Autoreply using a template
Use a Run a Script rule to autoreply to a message using a template. Include the original message or reply to a web form-generated message.

Macros to send messages using a specific account
Macro samples to send messages from a specific email account or email address you have permission to send as.
How to use an ItemAdd Macro
An ItemAdd macro watches a specific folder and runs a macro on it as messages are dropped into it, using any method: using rules, dragging messages to the folder, using the move or copy to folder command, or even copy and paste in place.
Set a reminder when accepting a meeting request
Use VBA to open an Outlook meeting request that was just added to the calendar after accepting the request in the Inbox. so you can set a reminder or make notes.

Use PowerShell to Export and Import Categories
How to use PowerShell to export, import or merge categories in different Outlook mailboxes.

Print a list of Outlook Categories and their Colors
How to use VBA to create a list of your Outlook categories and their assigned colors. For Microsoft Outlook 2007 and up.
Add recurring travel appointments to recurring appointments
Add travel appointments before and after recurring appointments as recurring appointments. This code sample was written by Rory. I figured out how to create recurring appointments that match the recurrence pattern of my master appointment. Sub AddTravelToMeeting() Dim olItem As AppointmentItem, olItems As Outlook.Items Dim strTravelOut As String Dim strTravelBack As String Dim iTravelMinutesOut As
To automatically add recipients to Contacts in Outlook using VBA
One thing that Outlook cannot do by itself is automatically create new entries in Contacts for people you send messages to. This VBA code sample by Sue Mosher provides a way to add recipients automatically. To avoid the Outlook security prompts, it uses the Redemption library, which provides a wrapper for Extended MAPI that does
Dismiss reminders for past calendar events
Two macros to remove reminder from appointments. The first macro removes the reminders as the appointment is created in a specific calendar folder. The other macro removes reminders from older items.

How to Create a Unified Inbox View
How to use create a Unified Inbox filter in Outlook 2010 or Outlook 2013 using VBA and a search query. Turn any frequently used search into a macro.