Email mailbox format

email-mailbox-format · version 1.0.0 · Communications · free, no key needed

Render a canonical RFC 5322 mailbox from decoded parts, without a delivery claim.

Use when you need to: render canonical rfc 5322 mailbox · format mailbox from local part and domain · quote display name words for a mailbox.

Decide before calling

Read the versioned contract and the supported scope below. Reuse email-mailbox-format@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use email-mailbox-format@1.0.0 for render canonical rfc 5322 mailbox. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

• render canonical rfc 5322 mailbox
• format mailbox from local part and domain
• quote display name words for a mailbox
• build name-addr from decoded parts
• render a domain literal mailbox
• write canonical addr-spec text
• הרכבת תיבת דואר תקנית

Not supported

• parse a raw mailbox string
• fold a header line to 78 characters
• encode RFC 2047 display names
• send mail or check that the domain exists

Behavior

• Inputs are already-decoded parts. local_part is quoted only when it is not a dot-atom. Each display word is an atom when it is 1*atext, otherwise one quoted-string. Words are joined by a single space. domain_form dot-atom (the default when omitted) writes a dot-atom; domain-literal writes [dtext] with no IP check.
• angles defaults to false and yields an addr-spec. angles true with no display words yields <addr-spec>. Display words require angles true. utf8 defaults to false; true allows RFC 6532 UTF-8 scalars and does not normalize or convert to A-labels.
• Omitted domain_form means dot-atom. Omitted display_words means no phrase. Case is preserved. This rendering is syntax only: no DNS lookup and no deliverability claim.

Input

• local_part (string, required): min length 0; max length 64
• domain (string, required): min length 0; max length 190
• domain_form (one of "dot-atom", "domain-literal", optional)
• display_words (array of string, optional): max items 8; each min length 0; each max length 64
• angles (boolean, optional)
• utf8 (boolean, optional)

Output

• mailbox (string, required): min length 3; max length 1600
• form (one of "addr-spec", "name-addr", required)

Limits

• max local part chars: 64
• max domain chars: 190
• max display words: 8
• max word chars: 64
• max output bytes: 2048

Example

Request input:

{
  "local_part": "john.q.public",
  "domain": "example.com",
  "display_words": [
    "Joe Q. Public"
  ],
  "angles": true
}

Response:

{
  "result": {
    "mailbox": "\"Joe Q. Public\" <john.q.public@example.com>",
    "form": "name-addr"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "email-mailbox-format",
  "version": "1.0.0",
  "input": {
    "local_part": "john.q.public",
    "domain": "example.com",
    "display_words": [
      "Joe Q. Public"
    ],
    "angles": true
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/email-mailbox-format/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"local_part":"john.q.public","domain":"example.com","display_words":["Joe Q. Public"],"angles":true}'

The machine-readable contract is at /v1/tools/email-mailbox-format/versions/1.0.0.

CLI

node cli.mjs run email-mailbox-format 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Email address list format: Format mailboxes and groups as one deterministic RFC 5322 address-list.
• Email mailbox parse: Parse one RFC 5322 mailbox into parts and canonical text, without a delivery claim.
• Email address list deduplicate: Drop duplicate mailboxes in an RFC 5322 address-list, keeping the first one.
• Email address list parse: Parse an RFC 5322 address-list into ordered mailboxes, groups, and a canonical form.
• Email address list validate: Check RFC 5322 address-list syntax, including dots, quotes, comments, and groups.
• Email mailbox validate: Check one RFC 5322 mailbox for syntax only and return a stable reason code.