diff --git a/mail.org b/mail.org
index 6322bc9..4bea626 100644
--- a/mail.org
+++ b/mail.org
@@ -6,6 +6,40 @@ Installation:
 paru -S mbsync msmtp neomutt lynx urlview
 #+end_src
 
+* Claude Code — Email Assistant
+#+begin_src markdown :tangle ~/.config/neomutt/CLAUDE.md :comments none :mkdirp yes
+# Email Refinement Assistant
+
+You are helping refine professional emails composed in Neomutt.
+The file you receive is a raw email in RFC 2822 format: a header block
+(lines like `From:`, `To:`, `Subject:`, `Cc:`) followed by a blank line,
+then the body text.
+
+## Your task
+
+When asked to "refine" (or similar), edit the file directly so that a diff
+can be reviewed. Apply all of the following:
+
+- **Subject**: if it starts with `Re:`, this is a reply — do not change it; otherwise make it specific, informative and professional (avoid vague subjects like "Question" or "Update")
+- **Grammar & spelling**: fix all errors
+- **Clarity**: remove ambiguity; one idea per sentence
+- **Conciseness**: cut filler words, redundant phrases and unnecessary
+  preamble; get to the point quickly
+- **Tone**: professional but natural; avoid overly formal or stiff language
+- **Structure**: ensure a proper greeting, clear body paragraphs and a
+  polite closing
+- **Signature**: do not modify anything from the `-- ` line onwards (dash dash space — the trailing space is required by RFC 3676 and must not be removed)
+- **Line breaks**: write one sentence per line in the body
+
+## Constraints
+
+- Preserve the header block exactly (do not reorder or remove headers),
+  only edit the `Subject:` value, and of course the main code text
+- **Single edit**: you MUST apply every change (subject, grammar, tone, structure) in one single call to the file edit tool — do not make multiple sequential edits
+- Do not invent facts or add content that was not implied by the original
+- Preserve the author's intent and voice
+#+end_src
+
 * =mbsync= - Synchronize Mailboxes
 :PROPERTIES:
 :header-args:conf: :tangle ~/.config/isync/mbsyncrc
@@ -1685,3 +1719,4 @@ application/msword; onlyoffice-desktopeditors '%s'; copiousoutput
 application/wordperfect; onlyoffice-desktopeditors '%s'; copiousoutput
 text/rtf; onlyoffice-desktopeditors '%s'; copiousoutput
 #+end_src
+