What is Sender Verify? April 27th, 2009
One of the topics that we frequently find ourselves discussing here at Idologic is Sender Verify. Pretty much your only interaction with this nifty little feature will be negative, because you will see this much-maligned error message: 550 Sender verify failed. This is the hallmark error that shows up when something doesn’t work; otherwise you would never even know this feature even existed, as it quietly hums along doing its diligent duty and keeping spam from your inbox.
Sender Verify works like this in a nutshell: It sends out a callback to a mail server when it receives mail to verify that the email address actually exists. This is accomplished by a series of checks that do simple tasks like check for a broken DNS setup or verify an MX entry. It’s a powerful tool for fighting spam because most spam has forged information and is not sent from a “real server” – yes that is one of those vague explanations, but put that on the shelf for now.
99% of the time, Sender Verify works just like it should. That is why you don’t even know it exists; email that should be delivered is indeed delivered and email that is spam and should not be delivered is rejected. There is no need for the resources of antispam/antivirus software to be brought to bear thanks to this utility.
When Sender Verify occasionally doesn’t work [when it should], it is typically a result of a different email configuration from the sending server. The tool functions by making the generally correct assumption that all mail servers follow a set of basic guidelines (which most all do). However, there are certain email systems out there that don’t exactly follow these guidelines for one reason or another. This does not make them wrong, nor does this make Sender Verify wrong.
These are the times that a support ticket is necessary. In order to help you continue functioning and receive the mail you expect to receive, Idologic, Inc. offers two solutions:
- Whitelist the “Offending” Mail Server. This is pretty simple; we grab the name of the mail server and add it to a special whitelist which will ensure safe passage of mail from that domain, as the actual sender verify checks are ignored. This is the recommended and most common solution.
- Opt your domain out of Sender Verify. This is the nuclear option, if you will. We will remove your domain from Sender Verify altogether. You’ll never be bothered by Sender Verify again, but the same is also true for spam email sent to your account. Spam amounts will increase. This path is for those that are concerned about Sender Verify or just are lucky enough to frequently find themselves in disagreement with Sender Verify.
If you need to use either of the two options, simply create a ticket with the helpdesk informing us of what you would like to do. Either option must be carried out by Idologic staff.
(And to let you in on a little secret, we are currently developing a tool for your Billing panel that will allow you to remove a domain from Sender Verify without opening up a ticket.)
I feel a bit like a broken record when I say this, but Idologic is always here to help. We will be happy to field any questions or assuage any concerns. Reach us 24/7/365 on the helpdesk at http://helpdesk.idologic.com/.