subscriptions10Q: Would you explain what tests are applied to classify an email address as a catchall address?
ReoonSupport
May 14, 2024A: Thanks for the query. You probably already know the meaning of catch-all. However, in short, the catch-all basically means that if you send an email to one address that does not exist, the email server will still accept it (that email can be internally forwarded to an admin email or get deleted). So if you send an email to an invalid address of a catch-all server, it should not hard-bounce (there can be a soft bounce, which is basically a reply email from that server, so technically not a bounce).
How we detect that: In order to detect the catch-all server, at first we verify the provided email address. If the response of that email is valid, we try to verify a certainly invalid email from that domain (randomly generated), for example, adfsag4gasdf4@example.com can be one certainly invalid randomly generated email from that domain. If the response is still valid, we can say that this email server accepts email at any of its addresses. So, it's a catch-all. There are a few other technological things involved, but this is the main principle.
Have a great day.
Verified purchaser
Thanks. With that, would all catch all domains be considered unsafe to send? I have my hosting with office 365. MS does not allow catch all's but does allow alias names to the same email. My email came back as a catch all and unsafe to send to and I would not consider that to be correct feedback.
If you trust your email list (i.e. your own subscribers), you can surely send emails to catch-all. However, for purchased or scraped email lists, it is better to avoid sending to catch-alls from your main domain.