The reason you get 100% Open Rates when you email specific companies is because those companies have bots enabled (security features) that open your email and check if you are sending anything malicious.
Open Rates are inflated in general.
It’s hard to tell if your domain is okay or burnt given the current information, but if everything is the same (lead list, copy) and you see a drop in replies, the first thing I think about is domain burn.
Domain reputation is also a scale vs (burnt or okay). Maybe you are landing in SPAM for some users and landing in the inbox for others?
With us, we try not to think about how to repair reputation for secondary domains as much. It’s tough to figure out the exact problem. Give your domain a break and just use new domains because the ROI is so high.
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Inbox Placement Tests:
Inbox Placement Tests are created when you send emails to a bunch of seed accounts. (Seed accounts are just accounts explicitly used for inbox placement tests.)
These accounts may or may not (most likely not) mimic real human email accounts.
So they have different security features.
They never have Mimecast, IronPort, or Proofpoint protection.
If some of those accounts are new, they won’t have similar security features compared to a bigger company.
You also send just 1 email to those accounts, compared to 50 emails a day to multiple other accounts.
So if 20% of your emails are going to SPAM, you will see a drop in reply rates, but inbox placement tests might show everything is okay.
That being said, it is not a perfect indication, but one of the indicators.
PS: I haven’t created my own Inbox placement tests, (We use other companies) so I don’t know all the technicalities behind it. This information is based on my personal experience
Ricardo R.