Mail title

Here are some examples of mail titles:

Business

• Invoice
• Payment Receipt
• Order Confirmation
• Shipping Notification
• Product Catalog
• Sales Quote
• Purchase Order

Personal

• Birthday Greeting
• Holiday Card
• Congratulations Message
• Get Well Soon Card
• Thank You Note
• Apology Letter
• Invitation to an Event

Formal

• Formal Letter
• Memorandum
• Notification of Meeting
• Agenda
• Minutes of Meeting
• Report Submission
• Request for Information

Informal

• Text Message
• Email
• Social Media Post
• Instant Message
• Chat Message
• Online Review
• Comment on a Blog Post

These are just a few examples, and there are many more types of mail titles depending on the context and purpose of the message.