same result returned, but one failed and one succeed

[landland]

For the same email, I get the exact same info object and same verifyCodes, but one passes and one fails. How come? For example, the code is

verifier.verify(email, options, function(err, info) {
        if (err) {
            console.log("smtp valid err ", err);
        } else {
            console.log("Success isSmtpCatchAll (T/F): " + info.success);
            console.log("Info: " + info.info);

            //Info object returns a code which representing a state of validation:

            //Connected to SMTP server and finished email verification
            console.log(info.code === verifyCodes.finishedVerification);

            // //Domain not found
            console.log(info.code === verifyCodes.domainNotFound);

            // //Email is not valid
            console.log(info.code === verifyCodes.invalidEmailStructure);

            // //No MX record in domain name
            console.log(info.code === verifyCodes.noMxRecords);

            // //SMTP connection timeout
            console.log(info.code === verifyCodes.SMTPConnectionTimeout);

            // //SMTP connection error
            console.log(info.code === verifyCodes.SMTPConnectionError);

        }
    });

But on one machine, the result is

Success Smtp Valid (T/F): true Info: a.jacobs@nottherealdomain.com is a valid address addr: a.jacobs@nottherealdomain.com code: 1 banner: 220 se6.mailspamprotection.com ESMTP Exim 134224 Fri, 15 Jun 2018 14:23:04 -0500

true false false false false false

And on another, the result is

Success Smtp Valid (T/F): false Info: a.jacobs@nottherealdomain.com is a invalid address addr: a.jacobs@nottherealdomain.com code: 1 banner: 220 se2.mailspamprotection.com ESMTP Exim 134224 Fri, 15 Jun 2018 14:22:35 -0500

true false false false false false

Any ideas? It's almost the exact same result, even the banner, except one is valid and the other invalid.