README
¶
vrf: An SMTP Address Verifier
Checks whether a single email address is deliverable. Exits successfully if so.
To install:
$ go get github.com/ransford/vrf
Is foo@bar.quux a deliverable email address?
$ vrf foo@bar.quux
foo@bar.quux is deliverable
$ vrf -quiet foo@bar.quux && echo "yes"
yes
What about oiwperwer@google.com?
$ vrf oiwperwer@google.com
oiwperwer@google.com is not deliverable
$ vrf -quiet oiwperwer@google.com || echo "no"
no
How it Works
vrf looks up the mail exchanger (MX) records for a given address, then
connects to the highest priority server in the list and goes partway through
the process of delivering an email messsage. Essentially:
> Client: Hello `domain.com` mail server!
> Server: Hello!
> Client: I have email for user `bob@domain.com`.
> Server: Sure, I'll accept it. ***OR*** Sorry, no such address.
> Client: Never mind.
> Server: Fine, whatever.
> Client: Bye!
> Server: Bye.
Technically speaking, vrf disconnects (politely, with RSET) after MAIL.
Documentation
¶
Overview ¶
vrf tests whether a given email address is likely to be deliverable.
To test whether an address is deliverable, i.e., whether it's a "valid" email address that can receive email, vrf finds an email server responsible for the domain, then conncts to that server and follows *most* of the protocol to deliver an email message, up to the point at which a message is actually delivered.
$ vrf good.guess@nowhere.biz good.guess@nowhere.biz is deliverable $ vrf bad.guess@nowhere.biz bad.guess@nowhere.biz is not deliverable # exits with 0 if deliverable, 1 otherwise. $ vrf -quiet good.guess@nowhere.biz && echo "good guess!" good guess!
Source Files