Shorten timeout for DNS lookups

[aripollak]

The default timeout for Resolv::DNS results in the validation for an unresponsive domain (like test123.com) taking at least 20 seconds. I'd like to reduce the timeout in validates_email_format_of using this since 20 seconds is way too long for a web request. Would you be okay with reducing the default timeout to 2 seconds with no retries (that would end up being 4 seconds total, one for A and one for MX)? Alternatively, validates_email_format_of can take an optional timeout number.

[fluke]

It should be a simple change. This function needs to take timeouts as well and we can have timeouts as an option to validates_email_format_of.

validates_email_format_of/lib/validates_email_format_of.rb

Line 14 in 14dd063

def self.validate_email_domain(email)

def self.validate_email_domain(email, timeouts = 2)
    domain = email.to_s.downcase.match(/\@(.+)/)[1]
    Resolv::DNS.open do |dns|
        dns.timeouts = timeouts
        @mx = dns.getresources(domain, Resolv::DNS::Resource::IN::MX) + dns.getresources(domain, Resolv::DNS::Resource::IN::A)
    end
    @mx.size > 0 ? true : false
end

[atomical]

If it times out does it return invalid for the e-mail?

[alexdunae]

Good idea. I've added that.

If it times out a ResolvTimeout is thrown.