Here's an odd SpamAssassin problem

I was just testing an email for a friend of a friend. Part of that testing involved running the email through my KBXSCORE checker. It came back with very few issues; most of the header bits are configured properly and the email is fully authenticated.

But I had a weirdly higher-than-expected SpamAssassin score, and when I looked at what rule caused the score to spike, it was this one: PDS_OTHER_BAD_TLD. This particular SpamAssassin rule is meant to warn users of "untrustworthy TLDs" (top level domains) like, for example, .click. Meaning that the makers of SpamAssassin believe that linking to a "dot click" domain is a spam sign.

But this email didn't link to a "dot click" domain. Or did it? I couldn't see it at first, but then I went through the text version with a fine tooth comb and here's what I saw (slightly redacted):

Thank you for subscribing to receive emails from (COMPANY). Get access to all the best brands & personalized service right in your neighborhood.Click here to view email in browser.             Privacy Policy   Terms of Use   Contact Us   Unsubscribe 2020 (COMPANY) Corporation. (COMPANY) Corporation and the (COMPANY) Corporation logo are registered trademarks of (COMPANY) Corporation. All rights reserved. Available at participating (COMPANY) locations and on (COMPANY).com unless otherwise noted. See product pages for details.  By texting XYYZ to ABCDEF from your mobile number, you consent to receive up to 8 autodialed marketing text messages per month from (COMPANY) to that number. Consent is not required to make a purchase. Message and Data rates apply. Text STOP to (NUMBER) to cancel. For assistance, text HELP for ABCDEF or call (NUMBER). Supported carriers include, but are not limited to, AT&T, Sprint, Boost, Virgin, T-Mobile, MetroPCS, 

Do you see it? It took me a minute. It's where two sentences run together: "...right in your neighborhood.Click here..." <- that missing space between "neighborhood." and "Click" is making SpamAssassin think it's a domain to link to. And it thinks that "neighborhood.click" is a bad domain, because it's been instructed to consider "dot click" domains to be untrustworthy.

The moral of the story? A missing space between sentences almost caused this email to go the spam folder, adding 1.8 points to its SpamAssassin score. That alone may not be enough to make an ISP junk this email message, but it highlights why you should check and test and make sure you're not accidentally doing thing that could cause or compound a deliverability issue.