If you are keeping important emails in your mailbox, which you can't delete, but you are unable to receive new emails, consider increasing the storage quota of your email address, i.e. the number of emails you can store in your mailbox.
Check your email service provider's website to see if they offer that as an option.
Some mailboxes come with limited storage space (e.g. 2 GB). Your mailbox storage might be full, i.e. has reached 2 GB, which would explain why you can't receive emails.
To fix this issue, delete all the emails you don't need. Delete emails from all folders, including the Junk folder.
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.