How to Set Up CalDAV Calendar Sync with Mailbux (Any Device)

Managing a busy schedule across multiple devices can be frustrating. You add a meeting on your phone, but it does not appear on your laptop. You update an event on your desktop, but your tablet still shows the old time. CalDAV calendar sync solves this problem by keeping your calendar data perfectly synchronized across every device you own — automatically.

With Mailbux, CalDAV support is built in. Every Mailbux account includes a full CalDAV server that works with iPhones, Android phones, Macs, PCs, and Linux — no extra software or paid add-ons required.

What Is CalDAV?

CalDAV (Calendaring Extensions to WebDAV) is an open internet standard for synchronizing calendar data between a server and multiple client devices. It is defined by RFC 4791 and is supported by virtually every calendar application on every platform.

Unlike proprietary sync services that lock you into a single ecosystem, CalDAV is vendor-neutral. Your calendar data lives on your own server, and you choose which apps access it. This means you can use Apple Calendar on your iPhone, GNOME Calendar on your Linux desktop, and Thunderbird on your Windows laptop — all showing the same events, updated in real time.

CalDAV supports everything you expect from a modern calendar system: recurring events, reminders, time zones, event invitations, shared calendars, and color-coded categories.

Why Use CalDAV with Mailbux?

When you create a Mailbux account, you get more than email. Your account includes a CalDAV calendar server tied to your custom domain. Here is why that matters:

Automatic sync across all devices — Add an event on your phone and it appears on your laptop within seconds. No manual export/import.
Your domain, your calendar — Calendar invitations are sent from your professional email address (e.g., you@yourdomain.com), not a generic Gmail or Outlook address.
No third-party dependency — Your calendar data stays on your Mailbux server. You do not need Google Calendar, iCloud, or any external service.
Works with every device — iPhone, Android, Mac, Windows, Linux. If the device has a calendar app, it almost certainly supports CalDAV.
Team sharing — Share calendars with team members using the same Mailbux domain for coordinated scheduling.

Mailbux CalDAV Server Settings

Before setting up any device, note these credentials — they are the same for every platform:

Setting	Value
CalDAV Server URL	https://my.mailbux.com/dav/calendars/
Base URL (for auto-discovery)	https://my.mailbux.com/dav/
Username	Your full email address (e.g., you@yourdomain.com)
Password	Your email account password

Important: Always use your full email address as the username — not just the part before the @ sign.

Setup Guide: iPhone and iPad (iOS / iPadOS)

Apple devices have native CalDAV support built into the Settings app. No third-party apps needed.

Open Settings on your iPhone or iPad
Tap Calendar (or Accounts on newer iOS versions)
Tap Accounts then Add Account
Select Other at the bottom of the list
Tap Add CalDAV Account
Enter the following:
- Server: my.mailbux.com
- Username: your full email address
- Password: your email password
- Description: Mailbux Calendar (or anything you like)
Tap Next — iOS will verify the connection and discover your calendars
Tap Save

Your Mailbux calendars will now appear in the Apple Calendar app alongside any iCloud or other calendars you already use. New events sync automatically in both directions.

Setup Guide: Android (DAVx5 or OpenSync)

Android does not include native CalDAV support, but free open-source apps handle it seamlessly.

Option A: DAVx5 (Recommended)

DAVx5 is available for free on F-Droid, or as a paid app on the Google Play Store. It is the most reliable CalDAV sync solution for Android.

Install DAVx5 from F-Droid or Google Play
Open DAVx5 and tap the + button to add a new account
Select Login with URL and username
Enter:
- Base URL: https://my.mailbux.com/dav/
- Username: your full email address
- Password: your email password
Tap Login — DAVx5 will auto-discover your calendars
Select the calendars you want to sync and tap the sync icon

DAVx5 runs in the background and keeps your calendars updated. Events will appear in your default Android calendar app (Google Calendar, Samsung Calendar, etc.).

Option B: OpenSync

OpenSync is another free CalDAV client for Android. The setup process is similar — add a CalDAV account using the base URL https://my.mailbux.com/dav/ with your full email address and password.

Setup Guide: macOS

macOS includes native CalDAV support in System Settings.

Open System Settings (or System Preferences on older macOS)
Click Internet Accounts
Click Add Other Account at the bottom
Select CalDAV Account
Set the Account Type to Manual (or Advanced)
Enter:
- Server: my.mailbux.com
- Username: your full email address
- Password: your email password
Click Sign In

Your Mailbux calendars will appear in the macOS Calendar app. They sync automatically whenever your Mac is online.

Setup Guide: Thunderbird (Windows, Mac, Linux)

Thunderbird supports CalDAV through the built-in calendar feature (Lightning) or with the TbSync add-on for easier setup.

Method 1: Built-in Calendar

Open Thunderbird and switch to the Calendar tab
Right-click in the calendar list and select New Calendar
Choose On the Network
Select CalDAV as the format
Enter the URL: https://my.mailbux.com/dav/calendars/
Enter your full email address and password when prompted
Thunderbird will discover and list your available calendars — select the ones you want

Method 2: TbSync Add-on

Install the TbSync add-on and the Provider for CalDAV & CardDAV add-on from Thunderbird Add-ons
Open TbSync from the Thunderbird menu
Click Account Actions then Add New Account and select CalDAV & CardDAV
Choose Automatic configuration and enter your full email address and password
If auto-discovery does not work, use manual configuration with server URL: https://my.mailbux.com/dav/
Select which calendars to sync and enable them

Setup Guide: Microsoft Outlook (Windows)

Outlook does not natively support CalDAV, but a free plugin bridges the gap.

Download and install the CalDAV Synchronizer plugin (free, open-source)
Restart Outlook after installation
Go to the CalDAV Synchronizer tab in Outlook's ribbon
Click Synchronization Profiles
Click the + button to add a new profile
Select Generic CalDAV/CardDAV
Enter:
- DAV URL: https://my.mailbux.com/dav/calendars/
- Username: your full email address
- Password: your email password
Click Test or Discover Settings to verify the connection
Select which Outlook calendar folder to sync and save

The plugin syncs on a configurable interval (default: every 30 minutes). You can also trigger a manual sync at any time from the toolbar.

Sharing Calendars with Team Members

CalDAV makes team calendar sharing straightforward. If multiple people on your team have Mailbux accounts under the same domain, you can share calendars between them:

Create a shared calendar — Through your Mailbux webmail interface, create a new calendar and set sharing permissions for specific team members.
Grant read or read/write access — Choose whether shared users can only view your events or also add and edit them.
Automatic discovery — When team members set up CalDAV on their devices, shared calendars appear automatically alongside their personal calendars.
Color coding — Most calendar apps let you assign different colors to each calendar, making it easy to distinguish personal events from shared team events at a glance.

This is especially useful for small businesses, agencies, and remote teams that need visibility into each other's availability without relying on a separate scheduling tool.

Troubleshooting Common Issues

Authentication Error or "Invalid Credentials"

Verify you are using your full email address as the username (e.g., you@yourdomain.com, not just you)
Double-check your password — try logging into Mailbux webmail to confirm it works
Make sure the server URL is exactly my.mailbux.com — do not use your own domain name as the server

Calendar Not Syncing or Events Missing

Check that your device has an active internet connection
On Android with DAVx5, ensure the app has permission to run in the background (battery optimization can kill sync)
Force a manual sync from your calendar app or DAVx5 to rule out timing issues
Verify the calendar is checked/enabled in your calendar app's sidebar — a disabled calendar will not show events even if they are synced

Duplicate Events Appearing

This usually happens when the same calendar account is added twice. Remove duplicate accounts from your device's calendar settings.
If you switched from importing .ics files to CalDAV sync, the imported events remain as local copies. Delete the local calendar to remove duplicates.
On Android, make sure you are not syncing the same calendar through both DAVx5 and another CalDAV app simultaneously.

Connection Timeout or Server Not Found

Confirm the server URL uses https:// (not http://)
Check that port 443 is not blocked by your network firewall
Try using the full URL https://my.mailbux.com/dav/calendars/ instead of just the server hostname

CalDAV vs. Proprietary Calendar Services

Services like Google Calendar and iCloud Calendar are convenient, but they come with trade-offs: your data lives on their servers under their terms, sync only works well within their ecosystem, and you have limited control over sharing and privacy.

With Mailbux CalDAV, you get the same seamless sync experience while keeping control. Your calendar data is part of your email hosting, tied to your own domain, and accessible from any standards-compliant application. No ecosystem lock-in. No ads. No data mining.

Get Started

If you already have a Mailbux account, CalDAV calendar sync is ready to use right now — just follow the setup guide for your device above. The entire process takes under five minutes, and once configured, your calendars stay in sync automatically.

New to Mailbux? Create your free account and get professional email with built-in calendar sync on your own custom domain. No credit card required.