# 🧨 IMAP Trigger fails with "Connection closed unexpectedly" on IONOS email – works in Outlook but not in n8n (cloud & VPS) **URL:** \ **Category:** Questions\ **Created:** [August 21, 2025, 10:21am UTC](https://community.n8n.io/t/imap-trigger-fails-with-connection-closed-unexpectedly-on-ionos-email-works-in-outlook-but-not-in-n8n-cloud-vps/172990 "2025-08-21T10:21:43Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Julio\_Valderrama](https://dub1.discourse-cdn.com/n8n/user_avatar/community.n8n.io/julio_valderrama/32/56020_2.png) [@Julio\_Valderrama](https://community.n8n.io/u/Julio_Valderrama)\ **Post date:** [August 21, 2025, 10:21am UTC](https://community.n8n.io/t/imap-trigger-fails-with-connection-closed-unexpectedly-on-ionos-email-works-in-outlook-but-not-in-n8n-cloud-vps/172990/1 "2025-08-21T10:21:43Z")
### 🧨 IMAP Trigger fails with “Connection closed unexpectedly” on IONOS email – works in Outlook but not in n8n (cloud & VPS) ## Hey everyone, I’ve been banging my head against this for hours, and after multiple attempts, I’m turning to the community for help. ## 🔧 Setup I’m trying to use the **IMAP Trigger node in n8n** to listen for new emails from an IONOS-hosted inbox. These are the connection details: - **Email** : `infoalquileres@barcelonetapremium.com` - **IMAP host** : `imap.ionos.es` _(also tried `imap.1und1.de`, which is what Outlook autodetects)_ - **Port** : `993` - **SSL/TLS** : ✅ Enabled - **Credentials** : correct (tested) n8n runs in two environments: - 🌩 **n8n cloud** (official) - 💻 **Self-hosted VPS via Docker Compose** * * * ## ✅ What I’ve confirmed - Works perfectly in **Outlook (IMAP)** using these same credentials, port, and host. - Ports are **not blocked** on the VPS or by my ISP. - I even tested from **Windows PowerShell using `openssl s_client`** and can establish the connection manually: ```powershell openssl s_client -connect imap.ionos.es:993 ``` ## So the connection is **definitely possible from outside**. ## ❌ Problem in n8n When I try to activate the IMAP Trigger node, I consistently get: > “Connection closed unexpectedly” > _(in the UI and logs)_ > This happens in **both** environments (cloud and VPS). I’ve tried: - Recreating the IMAP node from scratch - Switching between `imap.ionos.es` and `imap.1und1.de` - Removing and re-adding credentials - Restarting containers, clearing volumes, forcing reconnect - Using alternative ports (587, 143 just to test) → rejected by server Still always the same result. * * * ## 🧪 Additional clues - Outlook says the IMAP connection is **SSL/TLS (recommended)** over `imap.1und1.de:993` — which works. - However, n8n can’t maintain or even establish the connection. - The same config works on Thunderbird as well. So it’s NOT 2FA, not wrong credentials, not IP block, and not port filtering. * * * ## 🧵 Related posts checked I’ve already read through: - [n8n forum post 1](http://community.n8n.io/t/n8n-bug-report-imap-trigger-not-working-after-a-period-of-time/47796) - [IMAP broken after period](http://community.n8n.io/t/error-imap-trigger/32544) - [IMAP Zoho bug](http://community.n8n.io/t/trying-to-connect-to-zoho-mail-through-imap/110036) - GitHub issues on reconnect bugs * * * ## 🧠 Hypotheses 1. **n8n’s IMAP client library is unable to complete SSL handshake** with this specific provider. 2. The IMAP node internally crashes or mismanages reconnect events and dies silently. 3. IONOS enforces a specific TLS version that n8n’s library isn’t defaulting to. 4. There’s a quirk in how n8n handles certificate validation for IONOS — or something incompatible with their STARTTLS/SSL implementation. * * * ## ❓What I need help with - Is this a known issue with `imap.ionos.es` or 1&1 IMAP in general? - Can I force n8n to log the full raw error? Or debug the SSL negotiation? - Would it make sense to try setting up a proxy IMAP forwarder to test in-between? I’d love any ideas — or if someone has IMAP working with an IONOS email, please share your exact config. Thanks in advance 🙏 Julio ## Describe the problem/error/question ## What is the error message (if any)? ## Please share your workflow ```auto (Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.) ``` ## Share the output returned by the last node ## Information on your n8n setup - **n8n version:** n8n@1.107.4 - **Database (default: SQLite): Cloud and Sqlite for self hosted** - **n8n EXECUTIONS\_PROCESS setting (default: own, main):** - **Running n8n via (Docker, npm, n8n cloud, desktop app):** - **Operating system:** ---
**Author:** ![hubschrauber](https://dub1.discourse-cdn.com/n8n/user_avatar/community.n8n.io/hubschrauber/32/46788_2.png) [@hubschrauber](https://community.n8n.io/u/hubschrauber)\ **Post date:** [August 21, 2025, 10:41pm UTC](https://community.n8n.io/t/imap-trigger-fails-with-connection-closed-unexpectedly-on-ionos-email-works-in-outlook-but-not-in-n8n-cloud-vps/172990/2 "2025-08-21T22:41:36Z")
Even if this doesn’t help you resolve your issues, maybe it will be context to help narrow it. I just tried the IMAP Trigger from n8n cloud to [imap.ionos.com](http://imap.ionos.com) (per [docs](https://www.ionos.com/help/email/general-topics/settings-for-your-email-programs-imap-pop3/)). It worked (authenticated and fetched a test message) using the account/mailbox id (like m111222333-3), **and** using the associated default email address as a user name. The issue you have **might** be limited to accessing the `imap.ionos.es` domain/servers. ---
**Author:** ![system](https://dub1.discourse-cdn.com/n8n/user_avatar/community.n8n.io/system/32/195824_2.png) [@system](https://community.n8n.io/u/system)\ **Post date:** [November 19, 2025, 10:41pm UTC](https://community.n8n.io/t/imap-trigger-fails-with-connection-closed-unexpectedly-on-ionos-email-works-in-outlook-but-not-in-n8n-cloud-vps/172990/3 "2025-11-19T22:41:59Z")
Closed on November 19, 2025, 10:41pm UTC This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.