Atlas / MCP servers / googlarz / Proton Mail Bridge Client

Proton Mail Bridge ClientBLOCK

Name: Proton Mail Bridge Client
Author: googlarz

mcp/googlarz/proton-mail-bridge-client

MCP server by googlarz · ai agents · claude · claude code · Audited 2026-10-08

Local-first Proton Mail MCP server and CLI via Proton Bridge. Search, draft, send and organize mail from Claude Desktop, Claude Code or any MCP client. 96 tools, read-only and send-to-self modes.

Verdict

BLOCK

Grade

Trust score

69 /100

Exposed tools

60 25r · 21w · 14d

Transport

stdio

License

MIT

Stars

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

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|  _ \|  _ \ / _ \_   _/ _ \| \ | | |  \/  |  / \  |_ _| |
| |_) | |_) | | | || || | | |  \| | | |\/| | / _ \  | || |
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|_|   |_| \_\\___/ |_| \___/|_| \_| |_|  |_/_/   \_\___|_____|
Bridge Client  ·  CLI + Claude Desktop MCP for Proton Mail

[](https://www.npmjs.com/package/proton-mail-bridge-client) [](https://github.com/googlarz/proton-mail-bridge-client/actions/workflows/ci.yml) [](LICENSE) [](https://nodejs.org) [](https://www.typescriptlang.org) [](https://modelcontextprotocol.io) [](https://github.com/googlarz/proton-mail-bridge-client) [](https://github.com/googlarz/proton-mail-bridge-client/commits/main) [](https://github.com/googlarz/proton-mail-bridge-client) [](https://glama.ai/mcp/servers/googlarz/proton-mail-bridge-client)

Give Claude Desktop (or Cline, or any MCP client) full access to your Proton Mail inbox: read, search, send, draft, triage threads, manage folders, save

Read from source at commit a27d1c5fe30aOBSERVED · 2026-10-08

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.

claude-code (npm)

claude mcp add proton-mail-bridge-client --env PROTONMAIL_PASSWORD=${PROTONMAIL_PASSWORD} -- npx -y [email protected]

Exposed tools (60)

25 read · 21 write · 14 destructive. Blast radius: 14 tools can delete or overwrite — an agent that can be talked into calling a tool can be talked into calling this one.

Tool	Risk	Description
`a`	read	desc
`archive_email`	write	Move a single email to the standard Archive folder. Use for messages that are resolved but worth keeping long-term. Prefer trash_email when the message is no longer needed. Prefer move_email to route to a custom folder. Prefer batch_email_action for archiving multiple emails at once.
`b`	read	desc
`bulk_move`	write	Move multiple emails to a target folder in one IMAP pass. Accepts either explicit emailIds[] or a match criteria object (XOR). Supports dryRun to preview. For single-message moves use move_email.
`bulk_update_labels`	destructive	Add or remove Proton labels on multiple messages simultaneously. Use when the same label change should apply to several messages. Labels are IMAP folders under Labels/ namespace. Accepts emailIds[] OR match+folder (XOR).
`cancel_reply_reminder`	destructive	Delete a reply reminder by the id set_reply_reminder or list_reply_reminders gave.
`cancel_send`	write	Cancel a send_email call that was queued because PROTONMAIL_SEND_DELAY_SECONDS is set. Only works while the item is still pending — once it has actually sent, this returns canceled: false. No effect (throws) if PROTONMAIL_SEND_DELAY_SECONDS is 0, since nothing is ever queued in that case.
`cancel_snooze`	read	Wake a snoozed email immediately, moving it back to its original folder before wakeAt. No effect (throws) if the snooze has already woken or was already canceled.
`clear_cache`	destructive	Evict all in-memory caches: folder list, message metadata, and analytics data. Use when cached data appears stale after external mailbox changes (e.g. folders modified via Proton webmail). Does NOT affect the persistent SQLite index — use clear_index for that.
`clear_index`	destructive	Delete the entire persistent SQLite mailbox index from disk. Use only to reset a corrupted or schema-incompatible index. After clearing, call sync_emails to rebuild. Irreversible — all indexed metadata and search history is lost. Does NOT clear in-memory caches — use clear_cache for that.
`create_folder`	write	Create a new mailbox folder via IMAP. Use
`create_label`	write	Create a Proton label (IMAP folder under Labels/ namespace). Idempotent — safe to call if the label may already exist. For folder creation use create_folder with a Folders/ prefix.
`create_template`	write	Save a reusable email template. Subject and body may contain {{variable}} placeholders (e.g. {{firstName}}), auto-detected and stored on the template. Fails if a template with the same name already exists — delete it first to replace it.
`delete_draft`	destructive	Permanently delete a locally saved draft from SQLite. Use to discard a draft you no longer need. Does NOT remove a matching draft from the Proton Drafts IMAP folder — that requires a separate mailbox action. Irreversible; requires confirmed:true when PROTONMAIL_CONFIRM_DESTRUCTIVE is enabled.
`delete_email`	destructive	Permanently delete a single email via IMAP expunge. Use only when certain the message is no longer needed. Prefer trash_email if recovery may be required. Prefer bulk_delete to delete multiple emails at once. Prefer delete_thread to delete all messages in a conversation. Irreversible.
`delete_folder`	destructive	Delete an empty mailbox folder via IMAP. The folder must contain no messages — move or trash all messages first. Do NOT delete system folders (INBOX, Sent, Trash, Archive, Spam). Irreversible; messages already removed cannot be recovered this way.
`delete_label`	destructive	Delete a Proton label (IMAP folder under Labels/ namespace). Deletes the label itself, not the messages — they remain in their other folders/labels. Irreversible. For deleting a folder use delete_folder with a Folders/ prefix.
`delete_template`	destructive	Delete a saved email template. Irreversible; requires confirmed:true when PROTONMAIL_CONFIRM_DESTRUCTIVE is enabled.
`delete_thread`	destructive	Delete all messages in a thread, identified by RFC 5322 Message-ID header. permanent:true permanently expunges; false moves to Trash. Use when you have the raw Message-ID. Prefer apply_thread_action with action
`empty_folder`	destructive	Permanently delete ALL messages in a folder at once. Prefer bulk_delete when removing a subset of messages rather than everything in the folder. Use only when the goal is to clear an entire folder (e.g. emptying Trash or Spam). Only available when PROTONMAIL_ALLOW_EMPTY_FOLDER=true. Irreversible.
`export_email`	write	Save a message
`flag_thread`	destructive	Add or remove IMAP flags across all messages in a thread, identified by RFC 5322 Message-ID header. Use when you have the raw Message-ID and want to flag an entire conversation at once. Prefer apply_thread_action with action
`forward_email`	read	Immediately forward an existing email to new recipients, preserving original attachments and prepending an optional note. Use when you have an emailId and want to re-route the message without review. Prefer create_forward_draft to stage a forward for review first. Requires PROTONMAIL_ALLOW_SEND.
`get_audit_logs`	write	Return recent entries from the persistent on-disk audit log of all write operations performed by this server. Use to review what mutations (sends, moves, deletes, draft operations) were executed across sessions. Prefer get_logs for debugging in-session behavior and transient connection errors.
`get_connection_status`	read	Check whether Proton Bridge SMTP and IMAP are reachable and return authentication status for each. Use to diagnose connectivity before sending or syncing, or when tools return connection errors. Returns individual pass/fail for each protocol, plus this server
`get_emails_by_ids`	read	Fetch full content for multiple emails by composite id in one call (max 25). Use to read a batch of specific messages from a prior get_emails/search_emails/search_indexed_emails result without one get_email_by_id round trip per message. One failed id does not fail the whole batch — check each result
`get_follow_up_candidates`	read	Return threads that appear overdue for follow-up based on age and pending-on state. Use when looking for outbound messages you sent that haven
`get_inbox_digest`	read	Return a structured inbox summary: unread counts, top actionable threads, and overdue threads where a reply is pending from you. Use as the starting point for an inbox review session to get an at-a-glance picture. Prefer get_actionable_threads for a deeper, filterable list of threads needing action.
`get_index_status`	write	Return metadata about the local SQLite email index: row count, last sync timestamp, index schema version, and per-folder coverage. Use to verify the index is fresh and complete before querying it with search_indexed_emails or get_threads. If the index is empty or stale, call sync_emails first.
`get_labels`	read	Return normalized Proton folders and labels from the local mailbox index, including message counts per label. Use to enumerate available labels before filtering with search_indexed_emails or get_threads. Prefer get_folders for live IMAP folder counts when the index may be stale.
`get_runtime_status`	read	Return the server
`get_template`	read	Get a single saved email template by id.
`get_thread_by_id`	read	Fetch the complete normalized thread record from the local index, including all messages, participants, labels, and full metadata. Use when you need all messages in a thread. Prefer get_thread_brief for a summarized quick view that avoids returning the full message list.
`get_unsubscribe_info`	read	Read the List-Unsubscribe header of a message and report how to unsubscribe from it — a mailto address, an https link, or both. Does not take any action. Use before unsubscribe_sender to see what
`import_email`	write	Import a raw RFC822 message (.eml content) into a folder via IMAP APPEND. Use to restore a backed-up message or migrate mail from another provider
`list_accounts`	read	List every configured Proton address (the primary Bridge login plus any additional addresses from PROTONMAIL_ACCOUNTS_JSON), each with its own IMAP/SMTP connection status and local index freshness. Use to see which accounts this server is managing, and each account
`list_remote_drafts`	read	List draft messages currently stored in the Proton Drafts IMAP folder on the server. Use to see drafts created via Proton webmail or mobile app that have not been synced locally. Prefer list_drafts to see drafts managed by this server. Requires an active IMAP connection.
`list_snoozed`	read	List every snoozed email, including its id, status, and wakeAt — use this to rediscover the id needed for cancel_snooze if it was lost with the conversation.
`list_templates`	read	List all saved email templates.
`mark_email_read`	read	Mark a single email as read or unread by setting the IMAP Seen flag. Use for individual triage or to reset read state. Prefer batch_email_action with action
`move_email`	write	Move a single email to any specified mailbox folder. Use when routing a message to a custom folder. Prefer archive_email to move to the standard Archive folder, or trash_email to move to Trash. Use get_folders first to confirm the target folder path.
`move_thread`	write	Move all messages in a thread to a destination folder, identified by its RFC 5322 Message-ID header. Use when you have the raw Message-ID (e.g. from email headers) and want to move the full conversation. Prefer apply_thread_action with action
`prepare_meeting_context`	read	Fetch recent threads and communication history for a person or company domain to prepare for a meeting or call. Use before a scheduled meeting to surface relevant recent correspondence. Provide at least one of person (name or email fragment) or domain. Returns matched threads sorted by recency.
`rename_folder`	write	Rename or move a mailbox folder to a new IMAP path. Existing messages are preserved in place. Do NOT rename system folders (INBOX, Sent, Trash, Archive, Spam). Refreshes the local folder cache after the operation.
`rename_label`	write	Rename a Proton label (IMAP folder under Labels/ namespace). Messages keep the label, just under the new name. For renaming a folder use rename_folder with a Folders/ prefix.
`render_template`	read	Render a saved template
`restore_email`	write	Move an email from Trash back to INBOX or to a specified folder. Use to undo a trash_email operation. Does not work on permanently deleted messages — only messages currently in Trash can be restored.
`run_doctor`	write	Run a comprehensive production health check covering SMTP auth, IMAP auth, optional IMAP IDLE probe, SQLite index integrity, sync-failed drafts, runtime policy validation, and what this server can/cannot do (capabilities). Also reports this server
`schedule_draft`	write	Queue a saved draft to send at a future time instead of immediately. IMPORTANT: this only fires while this MCP server process stays running (it
`search_emails`	read	Search emails via live IMAP filters, across ALL configured accounts by default (accounts are queried one at a time; pass
`search_indexed_emails`	read	Search the local SQLite mailbox index (of ALL configured accounts by default; pass
`star_email`	read	Star or unstar a single email using the IMAP Flagged flag. Use to bookmark an important message for later follow-up. Prefer batch_email_action with action
`sync_draft_to_remote`	destructive	Force-push a locally saved draft to the Proton Drafts IMAP folder and return the remote UID. Use when a draft was created with syncToRemote:false or when the automatic sync failed. Do NOT use this if PROTONMAIL_ALLOW_REMOTE_DRAFT_SYNC is false — the call will be rejected.
`sync_folders`	write	Refresh the in-memory folder list from the IMAP server and return the updated list. Use when folders have been created, renamed, or deleted externally (e.g. via Proton webmail) and get_folders is returning stale data. Prefer get_folders for a read-only view that does not force a refresh.
`top_senders`	read	Return a frequency table of the top senders in a folder over a date range. Keyed on the sender address, not the display name, so display-name spoofing does not conflate different senders. Use for inbox analytics, unsubscribe triage, and contact discovery.
`trash_email`	write	Move a single email to the Trash folder. Messages in Trash can be recovered with restore_email. Use instead of delete_email when you may want to recover the message later. Prefer batch_email_action with action
`unsubscribe_sender`	write	Execute the mailto: variant of a message
`update_draft`	write	Update an existing locally saved draft
`update_message_labels`	destructive	Add or remove Proton labels on a single message without moving it. Prefer bulk_update_labels to apply label changes across multiple messages. Labels live under the Labels/ namespace (e.g.
`wait_for_mailbox_changes`	read	Open an IMAP IDLE session and block until a mailbox change event arrives or the timeout expires. Use to detect real-time inbox activity without polling. Returns whether a change was observed. Always returns within timeoutSeconds plus a few seconds

Trust audit

BLOCKgrade D · trust 69/100 Do not install this without reading the findings. The audit found something that could harm you or your machine.

Layer	What it checks	Result
L0	Provenance & inventory	PASS
L1	Static analysis of the code	FAIL
L2	Instruction surface (what it tells the agent)	PASS
L3	Class-specific surface	WARN
L4	Behavioural (sandbox)	SKIPPED

What the source does

Filesystem: declared (1 observation(s))
Network: declared (3 observation(s))
Shell: none-observed
Dependencies: not all pinned
Secrets in source: none-found

Findings (17)

HIGHNetwork egress · net.tls_off · CWE-200, CWE-319

src/services/simple-imap-service.ts:852

tls: this.shouldRelaxTlsVerification() ? { rejectUnauthorized: false } : undefined,

Why it matters. certificate verification is disabled

Fix. leave verification on

HIGHNetwork egress · net.tls_off · CWE-200, CWE-319

src/services/smtp-service.ts:239

tls: isLocalhost ? { rejectUnauthorized: false } : undefined,

Why it matters. certificate verification is disabled

Fix. leave verification on

MEDIUMFilesystem / path · mcp.destructive_tools · CWE-22, CWE-59

bulk_update_labels, cancel_reply_reminder, clear_cache, clear_index, delete_draft, delete_email, delete_folder, delete_label, delete_template, delete_thread, empty_folder, flag_thread, sync_draft_to_r

Why it matters. 14 tool(s) can delete or overwrite

Fix. prefer a read-only mode or scoped tokens; the page states the blast radius