Exchanger doesn't check if the new options are different before using the cache

[PMajesty]

If you try to validate an email address without dns_lookup: :off option before trying to validate it again, but now using the option dns_lookup: :off, the gem will still try to validate by DNS, because this line doesn't check if the config is any different before deleting the proposed host: https://github.com/afair/email_address/blob/fe055a96d7a5ffe2ec76ebfc47203e059e1f0096/lib/email_address/exchanger.rb#L14