- You have mistyped your email address (i.e. your email was either sent nowhere, or elsewhere)
- Your email address can't receive email (i.e. you've exceeded your quota, your spam filter doesn't allow *.psm file attachments, your spam filter requires a human to answer a challenge, your MX domain isn't configured, etc)
DO NOT type your email address with your keyboard. Let your browser auto-fill it for you. Carbon-based life forms are prone to human error and keyboard malfunction (looking at you, MacBook Butterfly Keyboard). The auto-fill will correctly type your email address every time.
DO use Gmail. It is imperative that you use Gmail. Have I stressed enough that you really really really should be using Gmail pretty please? Gmail will correctly receive your important email every time.
If you have not received your license, please contact Paddle (our payment processor) so they can look up your order number via your payment details and resend your license.
Memoirs of an Email Server:
Well, your specific problem was a 5.1.2 error. Which means you should: Check the "prontonmail.com" part of "…@prontonmail.com" for misspellings or missing letters.
No MX for gmaill.com
No MX for yshoo.com
No MX for gmail.om
No MX for gnail.com
No MX for hotmail.cocm
No MX for hotmail.xom
No MX for outlook.con
No MX for optonline.ent
5.7.1 <…@gail.com>: Recipient address rejected: this address does not exist
5.1.1 The email account that you tried to reach does not exist. Please try 5.1.1 double-checking the recipient's email address for typos or 5.1.1 unnecessary spaces. Learn more at 5.1.1 https://support.google.com/mail/?p=NoSuchUser
550 5.4.1 Recipient address rejected: Access denied [prod.protection.outlook.com]
550 5.1.1 Recipient address rejected: User does not exist.
Recipient address rejected: No need for spam. Try again later!
Not delivering to previously bounced address
Server response: 550 5.7.1 The user or domain that you are sending to (or from) has a policy that 5.7.1 prohibited the mail that you sent. Please contact your domain 5.7.1 administrator for further details. For more information, please visit 5.7.1 https://support.google.com/a/answer/172179
452 4.2.2 The email account that you tried to reach is over quota. Please direct 4.2.2 the recipient to 4.2.2 https://support.google.com/mail/?p=OverQuotaTemp