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.

Example Safe Messages

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