If your emails are not downloading in Mail, there could be several reasons for this issue. Here are some steps you can take to resolve the problem:
1. Check your internet connection: Make sure you have an active internet connection, as emails won't download if you're not connected to the internet.
2. Check your email settings: Ensure your email account settings are correctly set up. Double-check incoming and outgoing email server details, username, and password.
3. Remove and add the account: Sometimes, removing and adding the account back again can resolve this issue. To remove an email account, go to Settings > Accounts & Password, then click on the email account, and select "Delete Account". Next, restart your device and add the email account back again.
4. Delete and re-add affected emails: Try removing and re-adding any affected emails to see if it fixes the issue.
5. Update your Mail app and software: Ensure your device is running on the latest software and the Mail app is up-to-date. Install any available updates.
6. Contact your email provider: If all the above steps didn't resolve the issue, contact your email provider for further assistance.
In summary, if your emails are not downloading in Mail, check your internet connection, email settings, remove and add the account, delete and re-add affected emails, update your Mail app and software, and contact your email provider if none of the above steps work.