IMAP Configuration

This page explains the IMAP Configuration screen in GoAdmio. It controls which IMAP server the webmail client (Roundcube) connects to when users read their mail. By default it points to the local server (localhost:143), but it can be pointed at another server's IP — for example, during a mail migration, or in a split-server setup where IMAP lives elsewhere.

Location: Admin Panel → Email → IMAP Configuration

Overview

The IMAP Configuration page sets the IMAP endpoint that Roundcube uses to fetch mailboxes for webmail users. It does not change where Postfix delivers incoming mail — it only changes where webmail reads mail from.

| Setting | Default | What it controls |
|---|---|---|
| Hostname | localhost | The IMAP server Roundcube connects to |
| Port | 143 | The IMAP port |
| IMAP Secure | None | Whether to use SSL/TLS for the IMAP connection |
| Use Short Login | Off | Whether to strip @domain.com before authenticating |

> Important: This page makes webmail read from another server's IMAP. It does not make Postfix/Dovecot fetch mail from another server. If your goal is to pull mail from an external mailbox (e.g., Gmail) into a local mailbox, that is a different feature — see Forward Email API or the mail-fetching options in your version.

Fields Explained

Hostname

The IMAP server hostname or IP.

| Value | Meaning |
|---|---|
| localhost or 127.0.0.1 | Local Dovecot (default) |
| mail.example.com | Another server by hostname |
| 203.0.113.50 | Another server by IP |
| imap.provider.com | A third-party IMAP provider |

> Tip: Use a hostname rather than a raw IP where possible — it survives IP changes and works correctly with TLS certificate validation.

Port

| Port | Use |
|---|---|
| 143 | IMAP with STARTTLS (upgrade to TLS after connecting) |
| 993 | IMAPS — IMAP over SSL/TLS from the start |

> Note: If you use port 993, set IMAP Secure to SSL/TLS. If you use port 143, set IMAP Secure to STARTTLS (if supported) or None.

IMAP Secure

| Value | Meaning |
|---|---|
| None | Plain IMAP — no encryption. Only safe on localhost or a trusted private network. |
| STARTTLS | Connect on 143, then upgrade to TLS. Recommended for remote servers. |
| SSL/TLS | Connect on 993 with TLS from the start. Recommended for remote servers. |

> Warning: Setting IMAP Secure to None while pointing at a remote server sends credentials in plaintext over the network. Always use STARTTLS or SSL/TLS for remote IMAP.

Use Short Login

| Value | Meaning |
|---|---|
| Off | Roundcube sends the full login (user@domain.com) to the IMAP server |
| On | Roundcube strips @domain.com and sends only user |

> Tip: Turn this On only if the remote IMAP server expects bare usernames (no domain part). Most modern IMAP servers expect the full address. Test before enabling.

How to Point Webmail at Another Server

1. Log in to the GoAdmio Admin Panel.
2. Navigate to Email → IMAP Configuration.
3. Set Hostname to the remote server's hostname or IP (e.g., mail.oldsrv.com or 203.0.113.50).
4. Set Port to match the remote server (143 for STARTTLS, 993 for SSL/TLS).
5. Set IMAP Secure to STARTTLS or SSL/TLS.
6. Set Use Short Login only if the remote server requires bare usernames.
7. Click Save.

Prerequisites

Before pointing to another server:

1. The remote IMAP server is reachable from this server on the chosen port.
2. Outbound port 143 or 993 is open in this server's firewall.
3. The remote server's firewall allows connections from this server's IP.
4. User credentials exist on the remote server — the same username/password must be valid there.
5. The remote server has a valid TLS certificate if using STARTTLS or SSL/TLS — otherwise Roundcube will refuse the connection.
6. Mail is already on the remote server — pointing webmail at an empty remote server shows empty inboxes.

Test plain IMAP

Test IMAPS