Periodically check functionality of body email addresses

[RichardTaylor]

This is a suggestion arising from WhatDoTheyKnow user support mail analysis.

About one person a day writes to the support team having experienced a bounce/error message when trying to make a request.

We could periodically run checks on body email addresses (perhaps just those where there isn't a recent concluded thread?) to check they're functional.

The kind of checks which could be done could be based on Perl module Mail::CheckUser:

• It checks the syntax of an email address
• It checks if there any MX records or A records for the domain part of the email address.
• It tries to connect to an email server directly via SMTP to check if mailbox is valid. Old versions of this module performed this check via the VRFY command. Now the module uses another check; it uses a combination of MAIL and RCPT commands which simulates sending an email. It can detect bad mailboxes in many cases.

Preventing sending messages to non-functional addresses would be preferable to a user getting a bounce/error message on a correspondence thread.

If the check was reliable enough non-functional contact addresses could just be removed, the system already deals nicely with bodies without an email address.

[garethrees]

https://github.com/rubygarage/truemail

[RichardTaylor]

We could do the kind of checks proposed here when we use a contact address for the first time.

On WhatDoTheyKnow we currently have a situation where we've added a new set of bodies which have just come into existence and while they've publicised email addresses many don't yet work.

Could this even be part of the CSV upload workflow - with an error/warning for non-functional email addresses.