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Steps to add your corporate email account in the macOS Mail app. Written for current macOS versions; menu names may differ slightly by version. Screenshots show the Turkish interface.
All the values you will use during setup are below. Replace yourdomain.com with your own domain name; the username is always your full email address, not just the "name" part.
The step-by-step email setup wizard asks for your email app and address, then guides you through every screen with settings tailored to your address. We never ask for your password.
Mail first tries to find the settings itself; for corporate addresses this usually fails and you enter the details manually.

Open Mail and follow Mail > Add Account from the top menu. Type your email address in the window that opens. Because your corporate address is not one of the ready-made providers, click the choose from a list link instead of Continue.

iCloud, Microsoft Exchange, Google, Yahoo and AOL are listed. For your corporate address, select the Other Mail Account row at the bottom.

Fill in the three fields and press the Sign In button. Mail first tries to find the settings itself; for corporate addresses this usually fails and the fields in the next step open.

The red "Unable to verify account name or password" warning is not an error; it means you need to enter the settings manually. Fill in the fields that open and click Sign In again. If the username field shows "Automatic", type your full email address.
After the account is added, select your account under Mail > Settings > Accounts and switch to the Server Settings tab. Untick Automatically manage connection settings, set the values as below and click Save.
Send yourself an email and check that you receive it. If you get an error while sending, check that the outgoing server (SMTP) username is your full email address and that the password is saved.
The server details are the same in all of them; only the look of the screens changes.
Outlook 365 and the new Outlook app
Classic Outlook versions (2013-2021)
iOS and iPadOS Mail app
Android phones and tablets
Windows, Mac and Linux