Sending email
- steve
- June 14, 2022
- Delivery improvement , Technical

SWAKS is a general purpose testing tool for SMTP. For basic SMTP testing it’s a more convenient, scriptable alternative to running a transaction by hand, but it also lets you test things that are difficult to do manually, such as authentication or TLS encryption.
It’s a perl script that installs fairly easily on OS X or any Linux/unix system (and can be installed on Windows, if you have perl installed there).
It’s pretty well documented, but it can be a bit overwhelming to start with. Here are some simple recipes:
Send a test email:
Tools that you run from the command line – i.e. from a terminal or shell window – are often more powerful and quicker to use than their GUI or web equivalents.
Read MoreRecipients can’t click through if you don’t exist
A tale of misconfigured DNS wrecking someone’s campaign.
I got mail this morning from A Large Computer Supplier, asking me to fill in a survey about them. I had some feedback for them, mostly along the lines of “It’s been two decades since I bought anything other than rackmount servers from you, maybe I’m not a good advertising target for $200 consumer laptops?” so I clicked the link.

(I’ve replaced the real domain with survey.example.com in this post, to protect the innocent, but everything else is authentic).
That’s not good. The friendly error messages web browsers give sometimes hide the underlying problem, but that looks like a DNS problem. Did they do something stupid, like putting the wrong URL in the mail they sent?