Yeah, I once circumvented gmail's antivirus detection by sending a (perfectly legitimate) installer executable as a txt file because gmail apparently just has/had a strict "no files with certain extensions" policy. And IIRC Zendesk applies the same rule to file attachments on support tickets.

I had pitched for my team to build a tiny widget that would send attachments to virustotal, but it would have required a license for commercial use and we never had a security incident with files coming into our support center so it never became a priority.