Testing a Mail Domain that may be blocking us

Finding a safe email address

While ESS will continue to strive to reduce the incidents of blocking, sometimes it is important to be able to send email to a recipient domain suspected of still blocking before closing out a ticket. Here are a few general recommendations and then specific examples

• Most blocking recipient domains will return an error code "554" like this one. In bounces, look for a 554 if you suspect email blocking

General Tips

• Many domains will return a 554 even if the address doesn't exist so something like gobledegook@domain.com will let you know if delivery should be accepted
• Try generic contact addresses like IT helpdesks, comment boxes, things that you know are checked regularly from
• CC an external, personal email account or an e-list on the message you send. You can then pro-actively check the send headers on the message and determine the outbound mail relay that passed the message in the first place.
• Tools: also the use of this site is helpful. verify-email.org

Example Safe Messages

Sending to these addresses will allow you to test a domain without contacting affected clients