1. Internal mails: These are communications within the organization, such as memos, reports, and updates.
2. External mails: These are communications with individuals or organizations outside of the company, such as letters, invoices, and proposals.
3. Official mails: These are formal communications related to official business matters, such as contracts, agreements, and legal documents.
4. Informal mails: These are casual communications, such as emails, messages, and notes, that do not require a formal tone.
5. Urgent mails: These are communications that require immediate attention or action, such as meeting requests, deadlines, or urgent requests.
6. Routine mails: These are regular communications that are part of daily operations, such as status updates, progress reports, and routine requests.
7. Marketing mails: These are communications related to marketing and promotional activities, such as advertisements, newsletters, and promotional offers.
8. Personal mails: These are communications of a personal nature, such as birthday greetings, thank you notes, or personal messages between colleagues.