3LT Mail & Fax
REMOTE · 3LGROUPTECHNOLOGY.COM
AI assistants send real USPS letters ($1 flat) and faxes ($0.50 flat) via MCP.
Available components
Last scanned (7 hours ago)
Scores higher than 79% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Documents and Files
Recent critical change
Authorization (28 Oct 2026). See the changelog before you install this server.
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security57
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation check failed: no authorisation is required to call this server, and it exposes a tool marked destructive (request_send). See how to fix → View diagnostics → Fail
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability77
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 944 tokens (~134/item across 7 items; 7 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 3 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 2 Nov 26 +1
- Stability: 0.97 → pass security
- 31 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 90 to 93. That category is still filling its 30-day observation window: 27 days of observed history at the previous scan, 28 at this one. The score rises as the window fills, whether or not the server changes.
- 29 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 83 to 87. That category is still filling its 30-day observation window: 25 days of observed history at the previous scan, 26 at this one. The score rises as the window fills, whether or not the server changes.
- 28 Oct 26 +2
- Authorization: unverified → fail ▼ critical
- Tool “request_send” is now declared destructive security
- Tool “send_fax” is now declared destructive security
- Destructive annotations: All 3 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation. functional
- Server version: 4.1.3 → 4.1.4 functional
- Tool “approve_fax” changed its title: Approve Fax → Approve a Fax cosmetic
- Tool “create_fax_draft” changed its title: Create Fax Draft → Draft a Fax cosmetic
- Tool “draft_letter” changed its title: Draft Letter → Draft a Letter cosmetic
- Tool “get_fax_status” changed its title: Get Fax Status → Check Fax Status cosmetic
- Tool “request_send” changed its title: Request Send → Request Letter Send cosmetic
- Tool “send_fax” changed its title: Send Fax → Send a Fax cosmetic
- Tool “send_status” changed its title: Send Status → Check Letter Send Status cosmetic
- 26 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 73 to 77. That category is still filling its 30-day observation window: 22 days of observed history at the previous scan, 23 at this one. The score rises as the window fills, whether or not the server changes.
- 23 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 63 to 67. That category is still filling its 30-day observation window: 19 days of observed history at the previous scan, 20 at this one. The score rises as the window fills, whether or not the server changes.
- 22 Oct 26 +1
- Schema quality: 173 → 134 ▲ functional
- Server version: 4.0.10 → 4.1.3 functional
- New tool “approve_fax” functional
- New tool “create_fax_draft” functional
- New tool “get_fax_status” functional
- New tool “send_fax” functional
- 20 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 53 to 57. That category is still filling its 30-day observation window: 16 days of observed history at the previous scan, 17 at this one. The score rises as the window fills, whether or not the server changes.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Probed https://3lgrouptechnology.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=3lgrouptechnology.com | CN=YE2,O=Let's Encrypt,C=US | 2 Oct 2026 | 31 Dec 2026 | ECDSA 256 | ECDSA-SHA384 | 5dbe5809b2d7b18b22e5766ef966f37bc1f |
| SANs: 3lgrouptechnology.com | ||||||
| CN=YE2,O=Let's Encrypt,C=US (CA) | CN=Root YE,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | ECDSA 384 | ECDSA-SHA384 | 4df3b15dd6c0784c507cd37b58e6f115 |
| CN=Root YE,O=ISRG,C=US (CA) | CN=ISRG Root X2,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | ECDSA-SHA384 | 872165fc34b6e5fba8add5b3705fb53a |
| CN=ISRG Root X2,O=Internet Security Research Group,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | ECDSA 384 | SHA256-RSA | 6c8f1dc727c7117f7baf853ac980f9cd |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of 3lgrouptechnology.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| 3lgrouptechnology.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://3lgrouptechnology.com/mcp | Verified | 200 | |
| http (plaintext) | http://3lgrouptechnology.com/mcp | HTTPS enforced | 308 | https://3lgrouptechnology.com/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
approve_fax Approve a Fax ~97
Approve a fax DRAFT so it can be transmitted. The content is re-screened at approval time. Only the key that created the fax can approve it. Nothing is transmitted by this call — send_fax does that.
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| fax_id | integer | yes | the fax_id returned by create_fax_draft. |
Structured output declared, but exposes no named fields.
No examples provided.
create_fax_draft Draft a Fax ~154
Create a fax DRAFT: validates the recipient number, counts the PDF's pages, screens its text, and returns a price quote (Phaxio per-page cost x pages + the flat $1.00 service fee). This NEVER transmits anything — call approve_fax, then send_fax.
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| description | – | – | optional label for your own records. |
| pdf_path | string | yes | path to the PDF file on the server to fax. |
| to_number | string | yes | recipient fax number — 10-digit US number or a full E.164 number starting with +. |
Structured output declared, but exposes no named fields.
No examples provided.
draft_letter Draft a Letter ~315
Create a letter DRAFT: verifies the recipient address with PostGrid, screens content, and returns a price quote. This NEVER mails anything. Pass EITHER html (letter body as an HTML string) OR pdf_path (path to a PDF file on the server). PDF text is extracted for screening; if extraction fails the draft is kept but flagged needs_review.
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| certified | boolean | – | OPT-IN ONLY — True for USPS Certified Mail with Electronic Receipt (tracked, signature on delivery). Defaults to False, which sends standard First Class mail. Only set True when the customer explicit… |
| color | boolean | – | True for color printing, False for black & white. |
| description | – | – | optional label for your own records. |
| from_address | object | yes | sender address dict, same shape as `to`. |
| html | – | – | letter body as an HTML string (use this OR pdf_path). |
| pdf_path | – | – | server-local path to a PDF to mail instead of html. |
| quantity | integer | – | number of identical letters (10+ gets the bulk rate). |
| to | object | yes | recipient address dict with name, address_line1, address_city, address_state, address_zip (US). |
Structured output declared, but exposes no named fields.
No examples provided.
get_fax_status Check Fax Status ~88
Check a fax: lifecycle status (DRAFT/APPROVED/SENT/FAILED), page count, quote, and — once sent — the live delivery status from Phaxio.
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| fax_id | integer | yes | the fax_id returned by create_fax_draft. |
Structured output declared, but exposes no named fields.
No examples provided.
request_send Request Letter Send ~113
Request that a draft be mailed. approval-tier keys: creates a PENDING request and returns a one-tap Allow/Deny approval_url for the human. Nothing is mailed until Allow. on_command keys: may auto-send inside guardrails (spend caps, content screening, anomaly detection); anything outside them stays PENDING.
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| draft_id | integer | yes | the draft_id returned by draft_letter. |
Structured output declared, but exposes no named fields.
No examples provided.
send_fax Send a Fax ~86
Transmit an APPROVED fax via Phaxio. Refuses drafts that were never approved and faxes that were already sent — a fax can be transmitted exactly once.
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| fax_id | integer | yes | the fax_id returned by create_fax_draft. |
Structured output declared, but exposes no named fields.
No examples provided.
send_status Check Letter Send Status ~91
Check a send request: status (PENDING/SENT/REJECTED/FAILED), the key's trust tier and tier decision, approval state (+approval_url while pending), and billing state (Stripe charge id when billed).
| Name | Type | Req | Description |
|---|---|---|---|
| api_key | string | yes | your 3L-Group Technology API key (lms_...). |
| request_id | integer | yes | the request_id returned by request_send. |
Structured output declared, but exposes no named fields.
No examples provided.
How do I install the 3LT Mail & Fax MCP server?
3LT Mail & Fax is a hosted endpoint at https://3lgrouptechnology.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · 3lgrouptechnology.com
claude mcp add --transport http com-3lgrouptechnology-3lt-letter-mail 'https://3lgrouptechnology.com/mcp'
What is the 3LT Mail & Fax MCP server?
3LT Mail & Fax is an MCP server listed in the public MCP registry as com.3lgrouptechnology/3lt-letter-mail. AI assistants send real USPS letters ($1 flat) and faxes ($0.50 flat) via MCP. This page covers its hosted endpoint (https://3lgrouptechnology.com/mcp).
Is the 3LT Mail & Fax MCP server safe to use?
3LT Mail & Fax scores 79 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the 3LT Mail & Fax MCP server expose?
3LT Mail & Fax exposes 7 tools: draft_letter, request_send, send_status, create_fax_draft, approve_fax, and 2 more. Their descriptions and schemas cost roughly 944 tokens of context every time the server is loaded.
Does the 3LT Mail & Fax MCP server require authentication?
No. We connected to 3LT Mail & Fax without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the 3LT Mail & Fax MCP server still maintained?
3LT Mail & Fax is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.