Use the ItemChange event to run a macro when an Outlook item is changed. In this example, a task is created when the Quick Click Flag is clicked.
Assign one task to several people
Use VBA to assign tasks to selected contacts. When a task is assigned to one person, you can keep a copy of the task in your Task folder and the person who accepts the task can send you updates. If the Task is assigned to multiple people, Outlook can’t track it and update the status.
VBA UserForm sample: Select from a list of templates
How to use a userform and VBA to select from a list of templates when creating a new message to a contact.
Migrating custom forms to a new Outlook version
When custom forms aren't working as expected, check to see if scripts are enabled in folders. I'll show you when to check.
Delete attachments from messages
How to keep the name of an attachment in a message after using VBA to remove the attachment.
Automatically create a task when sending a message
How to automatically create tasks for message you send using a VBA macro.
Use Instant search to find messages from a contact
Use VBA to create an Instant Search query for a selected contact or for messages sent to and from an email address. Can use this macro to search for journal items in Outlook 2013.
How to set a flag to follow up using VBA
You can edit the Flag to Follow up field text each time you flag a message, but you can't save the changes permanently, or even temporarily in an MRU list. However, you can use VBA to set flags, which will allow you to save custom Flag to text, as well as custom reminder times and start or due dates.
Export (Save) Outlook Contact Photos
Use VBA to export a photo from a contact and save it to the hard drive. Use a second macro to add the photo to a new contact.
Get Outlook's Internet Headers using VBA or PowerShell
Use this code sample and function to display the Internet header of selected message in a new message form.