--- title: How to bulk upload mailboxes description: Step-by-step guide to adding multiple mailboxes via CSV file --- [Skip to content](https://support.warmy.io/knowledge/how-to-bulk-upload-mailboxes-in-warmy#main-content) English Show submenu for translations ![Group 1261151152.png\]](https://support.warmy.io/hs-fs/hubfs/Group%201261151152.png?width=50&height=50&name=Group%201261151152.png) Open main navigation Close main navigation - English Show submenu for translations - [Go to warmy.io](https://www.warmy.io/) [Go to warmy.io](https://www.warmy.io/) Hey there Warmer! How can we help? 🙏 - There are no suggestions because the search field is empty. 1. [Help Center](https://support.warmy.io/knowledge?hsLang=en) 2. [Connection Guide](https://support.warmy.io/knowledge/connection-guide?hsLang=en) # How to bulk upload mailboxes ## Step-by-step guide to adding multiple mailboxes via CSV file                                                                                                                               🎧 Prefer to listen? Hit play to hear this article read aloud. ### **                            🚀 Getting Started!** If you need to connect multiple mailboxes to Warmy at once, theBulk Upload feature makes this process quick and efficient. Instead of manually connecting each mailbox, which can be time-consuming, you can upload a CSV file with all the necessary information. This allows you to save time and ensure that all mailboxes are connected correctly. Follow the steps below to ensure a smooth setup. Only SMTP and IMAP connections are supported for bulk upload. Connecting with **IMAP only, without SMTP, is not possible.** ### 📌 How to Bulk Upload Mailboxes. 1. **Open the Bulk Upload Option.** - Navigate to the **+Add Mailbox** tab and select **Bulk Upload**.![](https://support.warmy.io/hs-fs/hubfs/image-png-Jun-16-2026-08-34-35-8513-PM.png?width=670&height=383&name=image-png-Jun-16-2026-08-34-35-8513-PM.png) 2. **Select Your Subscription Plan.** - Choose the subscription under which the mailboxes will be added.![](https://support.warmy.io/hs-fs/hubfs/image-png-Jun-16-2026-08-42-28-4474-PM.png?width=670&height=347&name=image-png-Jun-16-2026-08-42-28-4474-PM.png) 3. **Download the CSV Template (Recommended).** - We provide a template file with the correct format for bulk upload. - This step is optional but highly recommended to ensure accuracy.![403shots\_so](https://support.warmy.io/hs-fs/hubfs/403shots_so.jpeg?width=670&height=223&name=403shots_so.jpeg) - The CSV template requires the following details for each mailbox: - **Email Address.** - **SMTP & IMAP Username.** - **SMTP & IMAP Password.** - **SMTP & IMAP Host & Port.** You can find this information in the **SMTP settings of your email server**. Different providers store these details in different places. We recommend visiting our [**Connections Guide**](https://support.warmy.io/knowledge/connection-guide?hsLang=en), selecting your provider, and checking where to find that data exactly. - Additional Fields & Recommendations: - **Use SMTP SSL/TLS** – We recommend setting this to `true`. - **Use IMAP SSL/TLS** – Also recommended to be `true` (or `false` if no IMAP). - **Use IMAP** – Set this to `true` if entering IMAP credentials, or `false` if not. - **From Name** – This is the Send from name displayed on emails. It can also be updated in the **Mailboxes** section. (It’s useful for [setting up inbox filters](https://support.warmy.io/knowledge/will-my-inbox-be-full-of-warmy-emails?hsLang=en).) - **Private Key** – Leave this empty unless required. Some providers, like Mailgun, may use it, and it's recommended (!) to fill it in when connecting Mailgun mailboxes. - **Authentication Method** – We recommend keeping this field set  **`login`** for all mailboxes. 4. **Upload Your CSV File** - Select and upload the file containing your mailbox details. **Only CSV format is supported.![](https://support.warmy.io/hs-fs/hubfs/image-png-Jun-16-2026-08-43-15-7375-PM.png?width=670&height=346&name=image-png-Jun-16-2026-08-43-15-7375-PM.png)** 5. **File Verification** - Warmy will scan the file and display the total number of mailboxes detected. ### ⚠️ Common Errors & Solutions 1. **Not Enough Available Slots** - The number of mailboxes in your file exceeds the available slots in your subscription. - **Solution:** Remove some mailboxes from the file or purchase additional plans (click **Upgrade**). 2. **File Exceeds the 1000 Mailbox Limit** - You can upload a maximum of **1000 mailboxes per file**. - **Solution:** Split your list into multiple files and upload them separately. 3. **Incorrect File Format or Data Errors** - Only **CSV** files are supported. - Incorrect or unrecognized mailbox details may cause upload failures. - **Solution:** Download the CSV template and ensure all data is correctly formatted before re-uploading. ### ✅ Completing the Upload - Click **Upload** once your file is ready. - You’ll be redirected to the **Mailboxes** page, where you’ll find the **Bulk Connections** section.![](https://support.warmy.io/hs-fs/hubfs/image-png-Jun-16-2026-08-45-07-6927-PM.png?width=670&height=232&name=image-png-Jun-16-2026-08-45-07-6927-PM.png) ### **🔍 Here, you can see:** - The name of the uploaded list. - The total number of mailboxes in the file. - How many were successfully connected. - How many failed to connect.![](https://support.warmy.io/hs-fs/hubfs/image-png-Jun-16-2026-08-46-37-9423-PM.png?width=670&height=248&name=image-png-Jun-16-2026-08-46-37-9423-PM.png) ### 🔎 Checking Status - ✅ **Green checkmark** – The list was successfully added (might not fully). - ❌ **Failed Mailboxes Report** – If some mailboxes fail to connect, you’ll see a **Download failed emails** button. Clicking it will let you download a file listing failed mailboxes along with reasons for failure.![](https://support.warmy.io/hs-fs/hubfs/image-png-Jun-16-2026-08-47-16-1631-PM.png?width=670&height=146&name=image-png-Jun-16-2026-08-47-16-1631-PM.png) ### 📝 Summary Bulk uploading in Warmy is a fast and efficient way to connect multiple mailboxes. To ensure a smooth process, download the CSV template, confirm you have enough available slots, and double-check data accuracy. If errors occur, use the Download failed emails option to troubleshoot.     #### [Need help? **Schedule a call with us 👨🏻‍💻**](https://www.warmy.io/book-a-support-call)   - [Connection Guide](https://support.warmy.io/knowledge/connection-guide?hsLang=en) - [General questions](https://support.warmy.io/knowledge/general-questions?hsLang=en) - [Technical questions](https://support.warmy.io/knowledge/technical-questions?hsLang=en#main-content) - [SPF and DKIM Configuration](https://support.warmy.io/knowledge/technical-questions?hsLang=en#spf-and-dkim-configuration) - [Subscription](https://support.warmy.io/knowledge/subscription?hsLang=en) - [Collaborate](https://support.warmy.io/knowledge/collaborate?hsLang=en) - [Features](https://support.warmy.io/knowledge/features?hsLang=en) - [Troubleshooting](https://support.warmy.io/knowledge/troubleshooting?hsLang=en#main-content) - [SMTP Errors](https://support.warmy.io/knowledge/troubleshooting?hsLang=en#smtp-errors) - [Service-related issues](https://support.warmy.io/knowledge/troubleshooting?hsLang=en#service-related-issues) - [Integrations](https://support.warmy.io/knowledge/integrations?hsLang=en#main-content) - [Seed List Automations](https://support.warmy.io/knowledge/integrations?hsLang=en#seed-list-automations) [![Chill listening crop-3](https://support.warmy.io/hs-fs/hubfs/Group%201261151152.png?width=24&height=24&name=Group%201261151152.png "Chill listening crop-3")](https://www.warmy.io/) warmy.io Help Center Copyright © 2026, AnyBiz LTD