Sometimes, guests do not receive emails such as password resets, email verification or signup notifications. We can verify our attempt to send the emails via Sendgrid. If we find that it is blocked by Outlook, we can follow this process to unblock the sender IP:
- We will assess what happened to the email by searching in the Brand's sub-user(or external account), under Activity for the email address. Note: Only emails from the last 30 days will appear under Activity.
550 5.7.1 Unfortunately, messages from [126.96.36.199] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3140). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [HE1EUR02FT048.eop-EUR02.prod.protection.outlook.com]
550 5.7.606 Access denied, banned sending IP [188.8.131.52]. To request removal from this list please visit https://sender.office.com/ and follow the directions. For more information please go to http://go.microsoft.com/fwlink/?LinkID=526655 (AS16012609) [BL2NAM02FT028.eop-nam02.prod.protection.outlook.com]
- If the emails were blocked, this indicates that the recipient mail server rejected the email, and that mail server is rejecting every email from the sender IP address. You can verify this in the same sub-user, under Suppressions > Blocks, by searching the same email.
- If one of the above messages are displayed in the Blocks list, mentioning Outlook, Live, or Hotmail, we will need to work with the guest (or the admin, if they also use Outlook) in order to follow the process outlined in the block response: "To request removal from this list please visit https://sender.office.com/ and follow the directions."
- After visiting the link, you will need to enter the IP address mentioned in the error in SendGrid, an accessible Outlook email(admin is preferable, but the guest if we don't have another Outlook email), and the Captcha data.
- An email will be sent to the entered email address with a confirmation link. Whoever has access to that email needs only to click that link, and then click Delist IP Address on the subsequent browser page.
- After 24 hours, the Sender IP will be delisted from the Office 365 Anti-Spam list, and you can reach back out and confirm that emails are being received again.
- Note: Best practice would be to review the reputation of the sending sub-user/IP in Sendgrid to ensure their reputation is high, and that this issue will not recur.
Note: These listed steps will fall under the responsibility of the brand to do. The reason is because the IP address was blocked outside of Punchh and it is the responsibility of the brand to get the IP removed from any lists. The steps listed above are valid but only a suggestion for the brand and not something that Support would do. For better strategy, the brand can reach out to their CSM.