In the Mail email client on macOS, you can sync your device with the calendar and contacts you have on our email server.
To set it up, just follow a few steps. The settings for both calendars and contacts are very similar and very simple.
Manual settings
1. Select System settings from the bottom menu.
In the settings, go to the Internet Accounts section

2. In the Internet Accounts section, add an account via the Add Account… button.

3. You will be presented with the option to select an account.
a. Calendar settings
Select CalDav account

4.a. You will see a window with the CalDAV account settings. Select Account Type Manual
Into the field User name enter your email
Enter the password for your email in the Password field

In the Server Address box, you must enter the address of your email server. You can find it by logging in to our webmail in the url line. For more detailed information, see General calendar and contact settings.
5.a. After filling in the fields, click on Sign In
The calendar syncs fine with the Mac calendar (depending on the number of events, this may take a few minutes).
b. Contact settings
Select CardDav account.

4.b. You will see a window with the CardDAV account settings. Select Account Type Manual
Into the field User name enter your email
Enter the password for your email in the Password field

In the Server Address box, you must enter the address of your email server. You can find it by logging in to our webmail in the URL line. For more detailed information, see General calendar and contact settings.
5.b. After filling in the fields, click on Sign In
The contacts sync fine with the Mac calendar (depending on the number of contacts, this may take a few minutes).