# How to import suppression lists via FTP?

Suppression lists allow you to block specific email addresses, domains, IP addresses, or user parts from receiving your mailings. In MAX accounts, you can sync and manage your suppression lists automatically by uploading CSV files to designated directories on the FTP server. FTP access is granted by your Customer Experience Manager.

Import modes
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Choose the directory that aligns with how you want to update your suppression list:

*   **Insert mode** (`/sync_suppressions/insert/`)  
    Adds a new suppression list if it doesn’t already exist, or appends new suppression rules/masks to an existing list. It is designed for incremental merging and routine updates.  
    In this mode you can only upload new masks. Files containing more than 10% of previously added masks are not allowed.
*   **Replace mode** (`/sync_suppressions/replace/`)  
    Permanently deletes the entire existing suppression list and replaces it with the new set of masks provided in the file. This action **cannot be reversed**.  
    Routine synchronization using Replace mode is strictly forbidden. If you need to perform a full reset or replace a list, please contact your Customer Experience Manager first.

Once a file is uploaded, processing starts automatically. It is **not possible to remove or update the file, or stop** the process.

The uploaded file is automatically deleted from the server once processing is completed.

File upload locations, naming & format
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To process a suppression list, the file must be prepared in a **standard CSV format** and it must be uploaded to one of two specific directories depending on the import mode you wish to use:

*   **`/sync_suppressions/insert/`**
*   **`/sync_suppressions/replace/`**

The file name must include **the account login** (email address), for example:

    accountlogin@example.com.csv
    

If you’re not sure what is your account login, you can get it from your Customer Experience Manager.

The **header row** must consist of a **single field** containing the **suppression list name** in 1 to 128 characters using only lowercase letters (`a-z`), numbers (`0-9`), and underscores (`_`).

Below the header, each row should contain a single mask in one of the following formats:

**Mask type**

**Example format**

**Description / details**

**Full email address**

`user@example.com`

Case-insensitive full email matching.

**User part**

`user@`

Useful for blocking role-based or generic prefixes (e.g., `info@`, `support@`). Case-insensitive.

**Domain part**

`@example.com`

Blocks all emails from a specific domain. Case-insensitive.

**MD5 hash**

`b12345c504c5638798eb6b511e6f49af`

An MD5 hash of the lowercased email address. Ideal if legal or compliance constraints prevent storing plain text addresses.

**IPv4 address**

`1.2.3.4`

Subscription IP in standard **dotted-decimal** format. Subnet classes are not supported.

**IPv6 address**

`0000:1111:aaaa:bbbb:cccc:dddd:eeee:ffff`

Must be a full, **uncompressed** 8-group colon format. Compressed forms (e.g., `0:0:0:0:0:0:0:1` or `0::1`) are **not allowed**.