Outlook adding a series of numbers @shadow.outlook.com to email

Hello Laura,
This issue typically occurs when there is a problem with the email account configuration or when Outlook is unable to authenticate or synchronize correctly with the email provider.

Here are some steps to troubleshoot and potentially resolve this issue on Mac:

Check Email Account Settings:
Ensure that your IMAP settings are correctly configured. Double-check your server settings in Outlook for Mac:

Incoming mail server (IMAP): Ensure that the correct SiteGround IMAP settings are used.
Outgoing mail server (SMTP): Check if the SMTP settings are correctly configured.
Re-authenticate or Re-add Account:
Sometimes re-authenticating the account or removing and re-adding the email account in Outlook can resolve authentication issues that might be causing the problem.

Update Outlook:
Ensure that you are using the latest version of Outlook for Mac. An outdated version may cause unexpected issues like the one you're experiencing.

Check for Proxy or VPN Issues:
If you’re using a VPN or proxy, try disabling it to see if the issue persists. Sometimes network interference can cause improper synchronization with the email server.

Clear Cached Data in Outlook:
Outlook stores local cached data that may become corrupted. You can try clearing this cache:

Go to "Preferences" > "Accounts" > Select your email account.
Click on the "Advanced" tab, then select "Server" and clear the cache.
Contact Email Provider (SiteGround):
If the problem persists, it may be worth reaching out to SiteGround support to ensure there are no server-side issues affecting email delivery or synchronization.

Best Regards,
Ali Koc