letter closing: with love/with affection [closed]

I am writing a letter to a friend of the opposite sex. The relationship is completely platonic and there is a significant age difference. We often write long letters to each other. I usually close the letters with "Regards" and sign with the first letter of my first name, but it sounds impersonal. I wonder if it is appropriate to close with "with love" or "with affection." but I don't want the person to take it the wrong way.

Thoughts?

Regards is the business equivalent of being technically polite but impersonal. The Balance provides a helpful diagram of closings to use in a business context. Here's an excerpt about a few entries on the more personal end:

Warm regards, Best wishes, and With appreciation - These letter closings are also appropriate once you have some knowledge or connection to the person to whom you are writing. Because they can relate back to the content of the letter, they can give closure to the point of the letter. Only use these if they make sense with the content of your letter.

Informal letters are more flexible in their closing. This resource lists lots of options, and it's hard to prescribe a single one because they depend so much on your personal style.

To answer your question directly, "With love" is not as forceful an ending as "love," and how it's understood will depend on the individual. It can be mistaken for a romantic overture, but there are also plenty of examples of friends trading letters that have "with love" in them. It's what etiquette writer Amy Vanderbilt recommends for someone known less intimately:

"In general, you would close a letter to a family member of close friend with "Love," "Best love," "Fondly," "Affectionately." If you are writing to someone you know less intimately you might use "All the best," "As always," "As ever," "With love," or, depending on the relationship, "Affectionately."

An example a few pages later uses "with love" to close a letter to a thank you note for "Mr. and Mrs. Thornberg." Given that Vanderbilt is speaking in a traditional vein of American etiquette, "with love" is probably fine.