This tutorial will show you how to set up a JetHost PRO IMAP email account on macOS Sierra/Mojave
We will be using a test email account email@yourdomain.com. Of course, you will have your own email address so substitute that in the appropriate places.
NOTE: Before proceeding, make sure you have a mailbox created.
1. In case you already have some account set up in your Mail – select Preferences in Mail menu (you can use shortcut CMD
+ , while Mail is opened on the screen): 
2. Go to Accounts tab, and click on + icon: 
If it is the first time you use Mail, you will see the pop-up where you can add the email account. Select Other Mail Account... option and hit Continue button: 
3. In Add a Mail Account window enter your full name, email address and email account password, then click on Sign In: 
4. Application will try to detect settings automatically. Disregard the result and fill in these boxes manually. Enter your account details:
- Email address: full email address
- Username: full email address
- Password: password for your email account
- Account type: IMAP
- Incoming Mail Server: imap.stackmail.com
- Outgoing Mail Server: smtp.stackmail.com
Click on Sign In once the details are filled: 
5. You may use both Mail and Notes here. Click Done button in order to finish account adding to Mail app: 
6. Once you click Done button, you will see the blank window without mailboxes. In order to open the mailboxes tree you need to click on Mailboxes button here: 
Now you will find your Inbox and Sent folders in the left sidebar: 
7. The next step is to verify that Incoming and Outgoing Mail Server settings are correct. While on Accounts tab of Preferences window click on Server Settings section: 
7.1 On the Server Settings tab make sure that Automatically manage connection settings is unchecked at the Incoming Mail Server (IMAP) section so that you can see the following menu with Port and Authentication fields: 
- Port: 993 for SSL or 143 for TLS
- Use TLS/SSL: should be enabled
- Authentication: set to Password
Then open Advanced IMAP Settings: 
Check Allow insecure authentication and click OK: 
7.2 On the Server Settings tab make sure that Automatically manage connection settings is unchecked at the Outgoing Mail Server (SMTP) section so that you can see the following menu with Port and Authentication fields: 
- Port: 465 for SSL or 587 for TLS
- Use TLS/SSL: should be enabled
- Authentication: set to Password
8. Once everything is done, click Save and feel free to start using Mail application on your macOS: 
That's it!
