[Your letterhead, if desired; if not, your return address]

[Date of letter-month, day, and year]

[Recipient's first and last names]
[Company name]
[Street or P.O. box address]
[City, State ZIP code]

Dear [recipient's name]:

I really regret that argument we had yesterday and want to apologize to you for anything I said that hurt your feelings or upset you. It makes me sad to know you're sad about things. I would really like to have a long conversation so we can both get things out in the open and resolve everything. Can we do this?

You are my everything, and I want us to right any wrongs and get back to having the incredible relationship that both of us really want.

All my love,

[Signature]

[Sender's first and last names]