Setting up email in OSX's default mail client is a resonably straightforward process using the default settings that Apples os detects.
If it comes up with an error after attempting to auto-configure however, the best approach is to delete the account as re-set the account up from scratch and try again.
If you are adding a new mailbox to your existing accounts managed via Apple Mail
If adding the mailbox as an additional account, you can add the new account by clicking the MAIL menu at the top of the screen, then ADD ACCOUNT.
From there follow the steps below:
Adding an account to Apple Mail
The screenshots / testing below is using OSX Big Sur
Step 1: Choose the OTHER MAIL ACCOUNT OPTION

Step 2: Enter your name, full email address and account password and Sign In.

Step 3: If the credentials provided are correct you will be presented with the following screen showing an error UNABLE TO VERIFY ACCOUNT AND PASSWORD.
This is because the email client hasnt been able to detect the mail server config.
- Enter the INCOMING and OUTGOING mailserver settings.
- You can leave the username on Automatic.
- You can choose IMAP or POP, but people have generally reported more success with a POP setup. If any issues with IMAP you can use POP, just remember to set your settings for keeping mail on the server to what you require via MAIL > ACCOUNTS in the mail menu in the toolbar at the top of OSX.
- Click the Sign In button to finish setting up the account.
As mentioned above, if any issues with a new mailbox you can delete the account and re-setup. You can try to modify the port settings via MAIL > ACCOUNTS (or MAIL > Preferences > Server Settings) as well.

There are several ways that email can be added/accessed on your domain name. Email forwarding, POP3 Mailbox Accounts, IMAP Mailbox Accounts, Google Suite/Apps, Microsoft Office 365, Server Name / MX Record change, Web Mail
You can now add new POP3 or IMAP email mailboxes directly through our CMS. Just click on the red email button under your domain name, then follow the directions
You can find your email mailbox settings via the DOMAINS / EMAILS button in the main menu.
Are you getting the following error message when sending a lot of emails from your desktop?
"Recipient address rejected: Rate limit reach, retry later"
Mar 2020 settings tested as working with the office365 desktop client.
IMAP settings for the new Outlook for Windows (replacing Windows Mail)
This is different to Outlook 365 - please see other help files.
Outlook for Mobile is not compatible with our mail servers when trying to connect via a secure (SSL) connection.
Do you have missing emails in your inbox? Have emails disappeared from your inbox?
Known good settings for the Thunderbird Email Client
Settings for Apple iOS / iPadOS products
You should normally be able to let OSX detect the settings, but here are the settings shown in you uncheck Automatically manage connection settings.
We've setup our own iphones this way, works well, it uses the iphone/MS Exchange integration method, even though you are really using GMAIL or Google Apps.
Learn how to move away from xtra/yahoo/hotmail/etc to an awesome gmail experience
Make sure you are using the incoming and outgoing mail servers provided by our instructions inside the CMS.
Incoming: mail.cms-tool.net
Outgoing: smtp.cms-tool.net
If you work from multiple locations or through different Internet Providers, then you may find changing your SMTP server all the time is a real hassle
If some emails are not being delivered to you, find out what spam filtering is happening on our servers
Use this procedure to determine the problem with your email
There are lots of steps in email going from our web forms to your inbox, learn the process here if you are needing to debug email issues
if you have the ability to define SPF records or whitelist SMTP servers, please use include:spf.cms-tool.net
Copies all emails and folders from old IMAP server to new IMAP server
Learn about how we block spam, and how email may be blocked by other ISPs also.
If you should want to view your DMARC reports, here is how to find them
If you have email services with us, you can have an auto responder if you are away on holiday. Here's how.