feat: add forward_email MCP tool

README.md

@@ -63,23 +63,24 @@ You can also configure the email server using environment variables, which is pa
 
 #### Available Environment Variables
 
-| Variable                                      | Description                                      | Default       | Required |
-| --------------------------------------------- | ------------------------------------------------ | ------------- | -------- |
-| `MCP_EMAIL_SERVER_ACCOUNT_NAME`               | Account identifier                               | `"default"`   | No       |
-| `MCP_EMAIL_SERVER_FULL_NAME`                  | Display name                                     | Email prefix  | No       |
-| `MCP_EMAIL_SERVER_EMAIL_ADDRESS`              | Email address                                    | -             | Yes      |
-| `MCP_EMAIL_SERVER_USER_NAME`                  | Login username                                   | Same as email | No       |
-| `MCP_EMAIL_SERVER_PASSWORD`                   | Email password                                   | -             | Yes      |
-| `MCP_EMAIL_SERVER_IMAP_HOST`                  | IMAP server host                                 | -             | Yes      |
-| `MCP_EMAIL_SERVER_IMAP_PORT`                  | IMAP server port                                 | `993`         | No       |
-| `MCP_EMAIL_SERVER_IMAP_SSL`                   | Enable IMAP SSL                                  | `true`        | No       |
-| `MCP_EMAIL_SERVER_SMTP_HOST`                  | SMTP server host                                 | -             | Yes      |
-| `MCP_EMAIL_SERVER_SMTP_PORT`                  | SMTP server port                                 | `465`         | No       |
-| `MCP_EMAIL_SERVER_SMTP_SSL`                   | Enable SMTP SSL                                  | `true`        | No       |
-| `MCP_EMAIL_SERVER_SMTP_START_SSL`             | Enable STARTTLS                                  | `false`       | No       |
-| `MCP_EMAIL_SERVER_ENABLE_ATTACHMENT_DOWNLOAD` | Enable attachment download                       | `false`       | No       |
-| `MCP_EMAIL_SERVER_SAVE_TO_SENT`               | Save sent emails to IMAP Sent folder             | `true`        | No       |
-| `MCP_EMAIL_SERVER_SENT_FOLDER_NAME`           | Custom Sent folder name (auto-detect if not set) | -             | No       |
+| Variable                                      | Description                                       | Default       | Required |
+| --------------------------------------------- | ------------------------------------------------- | ------------- | -------- |
+| `MCP_EMAIL_SERVER_ACCOUNT_NAME`               | Account identifier                                | `"default"`   | No       |
+| `MCP_EMAIL_SERVER_FULL_NAME`                  | Display name                                      | Email prefix  | No       |
+| `MCP_EMAIL_SERVER_EMAIL_ADDRESS`              | Email address                                     | -             | Yes      |
+| `MCP_EMAIL_SERVER_USER_NAME`                  | Login username                                    | Same as email | No       |
+| `MCP_EMAIL_SERVER_PASSWORD`                   | Email password                                    | -             | Yes      |
+| `MCP_EMAIL_SERVER_IMAP_HOST`                  | IMAP server host                                  | -             | Yes      |
+| `MCP_EMAIL_SERVER_IMAP_PORT`                  | IMAP server port                                  | `993`         | No       |
+| `MCP_EMAIL_SERVER_IMAP_SSL`                   | Enable IMAP SSL                                   | `true`        | No       |
+| `MCP_EMAIL_SERVER_SMTP_HOST`                  | SMTP server host                                  | -             | Yes      |
+| `MCP_EMAIL_SERVER_SMTP_PORT`                  | SMTP server port                                  | `465`         | No       |
+| `MCP_EMAIL_SERVER_SMTP_SSL`                   | Enable SMTP SSL                                   | `true`        | No       |
+| `MCP_EMAIL_SERVER_SMTP_START_SSL`             | Enable STARTTLS                                   | `false`       | No       |
+| `MCP_EMAIL_SERVER_SMTP_VERIFY_SSL`            | Verify SSL certificates (disable for self-signed) | `true`        | No       |
+| `MCP_EMAIL_SERVER_ENABLE_ATTACHMENT_DOWNLOAD` | Enable attachment download                        | `false`       | No       |
+| `MCP_EMAIL_SERVER_SAVE_TO_SENT`               | Save sent emails to IMAP Sent folder              | `true`        | No       |
+| `MCP_EMAIL_SERVER_SENT_FOLDER_NAME`           | Custom Sent folder name (auto-detect if not set)  | -             | No       |
 
 ### Enabling Attachment Downloads
 
@@ -150,6 +151,35 @@ sent_folder_name = "INBOX.Sent"
 
 **To disable saving to Sent folder**, set `MCP_EMAIL_SERVER_SAVE_TO_SENT=false` or `save_to_sent = false` in your TOML config.
 
+### Self-Signed Certificates (e.g., ProtonMail Bridge)
+
+If you're using a local mail server with self-signed certificates (like ProtonMail Bridge), you'll need to disable SSL certificate verification:
+
+```json
+{
+  "mcpServers": {
+    "zerolib-email": {
+      "command": "uvx",
+      "args": ["mcp-email-server@latest", "stdio"],
+      "env": {
+        "MCP_EMAIL_SERVER_SMTP_VERIFY_SSL": "false"
+      }
+    }
+  }
+}
+```
+
+Or in TOML configuration:
+
+```toml
+[[emails]]
+account_name = "protonmail"
+# ... other settings ...
+
+[emails.outgoing]
+verify_ssl = false
+```
+
 For separate IMAP/SMTP credentials, you can also use:
 
 - `MCP_EMAIL_SERVER_IMAP_USER_NAME` / `MCP_EMAIL_SERVER_IMAP_PASSWORD`
@@ -217,6 +247,22 @@ await send_email(
 
 The `in_reply_to` parameter sets the `In-Reply-To` header, and `references` sets the `References` header. Both are used by email clients to thread conversations properly.
 
+### Forwarding Emails
+
+To forward an email to new recipients:
+
+```python
+result = await forward_email(
+    account_name="work",
+    email_id="123",
+    recipients=["colleague@example.com"],
+    additional_message="FYI - please see below.",
+)
+print(f"Forwarded to: {result.forwarded_to}")
+```
+
+The forward preserves the original email's formatting (HTML or plain text) and includes attachments by default. Use `include_attachments=False` to forward without attachments.
+
 ## Development
 
 This project is managed using [uv](https://github.com/ai-zerolab/uv).

mcp_email_server/app.py

@@ -15,6 +15,7 @@
     AttachmentDownloadResponse,
     EmailContentBatchResponse,
     EmailMetadataPageResponse,
+    ForwardEmailResponse,
 )
 
 mcp = FastMCP("email")
@@ -204,3 +205,41 @@ async def download_attachment(
 
     handler = dispatch_handler(account_name)
     return await handler.download_attachment(email_id, attachment_name, save_path, mailbox)
+
+
+@mcp.tool(description="Forward an email to new recipients with original body and attachments.")
+async def forward_email(
+    account_name: Annotated[str, Field(description="The name of the email account.")],
+    email_id: Annotated[
+        str,
+        Field(description="The email_id to forward (obtained from list_emails_metadata)."),
+    ],
+    recipients: Annotated[list[str], Field(description="List of recipient email addresses to forward to.")],
+    from_address: Annotated[
+        str | None,
+        Field(
+            default=None,
+            description="Override the sender address. If not specified, uses the account's default email address.",
+        ),
+    ] = None,
+    additional_message: Annotated[
+        str | None,
+        Field(default=None, description="Optional message to include before the forwarded content."),
+    ] = None,
+    include_attachments: Annotated[
+        bool,
+        Field(default=True, description="Whether to include the original attachments in the forwarded email."),
+    ] = True,
+    mailbox: Annotated[
+        str, Field(default="INBOX", description="The mailbox containing the email to forward.")
+    ] = "INBOX",
+) -> ForwardEmailResponse:
+    handler = dispatch_handler(account_name)
+    return await handler.forward_email(
+        email_id=email_id,
+        recipients=recipients,
+        from_address=from_address,
+        additional_message=additional_message,
+        include_attachments=include_attachments,
+        mailbox=mailbox,
+    )

mcp_email_server/config.py

@@ -29,6 +29,7 @@ class EmailServer(BaseModel):
     port: int
     use_ssl: bool = True  # Usually port 465
     start_ssl: bool = False  # Usually port 587
+    verify_ssl: bool = True  # Set to False for self-signed certificates (e.g., ProtonMail Bridge)
 
     def masked(self) -> EmailServer:
         return self.model_copy(update={"password": "********"})
@@ -96,6 +97,7 @@ def init(
         smtp_port: int = 465,
         smtp_ssl: bool = True,
         smtp_start_ssl: bool = False,
+        smtp_verify_ssl: bool = True,
         smtp_user_name: str | None = None,
         smtp_password: str | None = None,
         save_to_sent: bool = True,
@@ -119,6 +121,7 @@ def init(
                 port=smtp_port,
                 use_ssl=smtp_ssl,
                 start_ssl=smtp_start_ssl,
+                verify_ssl=smtp_verify_ssl,
             ),
             save_to_sent=save_to_sent,
             sent_folder_name=sent_folder_name,
@@ -141,6 +144,7 @@ def from_env(cls) -> EmailSettings | None:
         - MCP_EMAIL_SERVER_SMTP_PORT (default: 465)
         - MCP_EMAIL_SERVER_SMTP_SSL (default: true)
         - MCP_EMAIL_SERVER_SMTP_START_SSL (default: false)
+        - MCP_EMAIL_SERVER_SMTP_VERIFY_SSL (default: true)
         - MCP_EMAIL_SERVER_SAVE_TO_SENT (default: true)
         - MCP_EMAIL_SERVER_SENT_FOLDER_NAME (default: auto-detect)
         """
@@ -183,6 +187,7 @@ def parse_bool(value: str | None, default: bool = True) -> bool:
                 smtp_port=int(os.getenv("MCP_EMAIL_SERVER_SMTP_PORT", "465")),
                 smtp_ssl=parse_bool(os.getenv("MCP_EMAIL_SERVER_SMTP_SSL"), True),
                 smtp_start_ssl=parse_bool(os.getenv("MCP_EMAIL_SERVER_SMTP_START_SSL"), False),
+                smtp_verify_ssl=parse_bool(os.getenv("MCP_EMAIL_SERVER_SMTP_VERIFY_SSL"), True),
                 smtp_user_name=os.getenv("MCP_EMAIL_SERVER_SMTP_USER_NAME", user_name),
                 smtp_password=os.getenv("MCP_EMAIL_SERVER_SMTP_PASSWORD", password),
                 imap_user_name=os.getenv("MCP_EMAIL_SERVER_IMAP_USER_NAME", user_name),

mcp_email_server/emails/__init__.py

@@ -7,6 +7,7 @@
         AttachmentDownloadResponse,
         EmailContentBatchResponse,
         EmailMetadataPageResponse,
+        ForwardEmailResponse,
     )
 
 
@@ -75,3 +76,28 @@ async def download_attachment(
         Returns:
             AttachmentDownloadResponse with download result information.
         """
+
+    @abc.abstractmethod
+    async def forward_email(
+        self,
+        email_id: str,
+        recipients: list[str],
+        from_address: str | None = None,
+        additional_message: str | None = None,
+        include_attachments: bool = True,
+        mailbox: str = "INBOX",
+    ) -> "ForwardEmailResponse":
+        """
+        Forward an email to new recipients.
+
+        Args:
+            email_id: The UID of the email to forward.
+            recipients: List of recipient email addresses.
+            from_address: Override sender address (uses account default if None).
+            additional_message: Optional message to prepend to the forwarded email.
+            include_attachments: Whether to include original attachments.
+            mailbox: The mailbox containing the email (default: "INBOX").
+
+        Returns:
+            ForwardEmailResponse with forward result information.
+        """