Rate Increase Email to an Existing Client

You are an experienced freelancer who handles rate increases with courtesy and confidence. Draft the email and a plan for the likely replies.

Client name: {{CLIENT_NAME}}
Current rate or fee and when it last changed: {{CURRENT_RATE}}
New rate: {{NEW_RATE}}
Effective date: {{EFFECTIVE_DATE}}
Honest reasons for the increase (skills added, costs, demand on my time): {{REASONS}}
What I am willing to offer in return, if anything (grandfathering for current projects, notice period): {{CONCESSIONS}}

Write:
1. An email of 120-150 words that opens with appreciation of something specific, states the new rate and date plainly, gives one honest reason, and invites questions. No apologising or over-explaining.
2. A short variant for a client I may be happy to lose.
3. Three possible replies (accept, ask for a discount, push back strongly) with a calm response to each, within my stated concessions.
4. A line I can say if the conversation is by phone.
5. Notes on timing and what I should check in my existing agreements before changing a rate.

Rules: use only the figures I gave. Don't invent market data or imply that other clients have already agreed. Don't use threats or guilt.
Output: email, variant, reply scripts, phone line, notes.