[sessy]

A valid business email is one where you should be able to receive and send mails. If you have a 'catch all' email id, the system does not accept that.

Having said that i must say our algorithm is deliberately a bit aggressive (so as to prevent spam).

Your email could very well be a false positive. Could you write to [e-mail] from the business email in question. I'll be happy to look into it and whitelist it.

[conquistadog]

What technical means do you use to detect a catch-all address? I know of no reliable method for that purpose, since receiving server cooperation would be required and could not be trusted.

[massaman_yams]

This won't detect a catch-all address, but will almost always detect a catch-all domain: send email to [long random string]@domain. Does it bounce or is it accepted?

[conquistadog]

How does the existence of a catch-all, of any kind, make it not a "valid business domain?"

[massaman_yams]

I'm not commenting on whether it's a good heuristic or not. Just a possible approach.

[yjftsjthsd-h]

Why would you block by that? I've worked places that intentionally did use the catch-all, mostly against misspellings.

[massaman_yams]

I use catchalls for my business domains too.