When writing a Mother's Day letter in English for an envelope, you should include the recipient's name and address. Here is a sample of what it could look like:
Envelope Address:
[Recipient's Street Address]
[Recipient's City], [Recipient's State/Province] [Recipient's Postal Code]
Dear Mom,
Happy Mother's Day! I hope this letter finds you in good health and high spirits. As another year passes, I can't help but marvel at all the love and care you have showered upon me. Your selflessness, patience, and unwavering support have shaped me into the person I am today.
I wanted to take this opportunity on Mother's Day to express my deepest gratitude for everything you do. From cooking my favorite meals to cheering me on during my endeavors, your presence has been a constant source of comfort and joy.