In the 90s (or maybe 00s) the company I worked for had a self-hosted web app (they mostly all were self-hosted, then) that did various things, but was also supp

In the 90s (or maybe 00s) the company I worked for had a self-hosted web app (they mostly all were self-hosted, then) that did various things, but was also supposed to be able to send email via whatever mail server you already had. But it didn't work for us. I forget the exact reason, but it was like some kind of text encoding issue where the mail server was expecting ASCII but the software was sending some weird non-ASCII character from EUC or SJIS that borked it. (It was a Japanese workflow app for internal company processes like calendaring, expense approvals, etc., so it had lots of user-entered strings that were in Japanese. UTF-8 existed, but... this product had legacy issues.) Unfortunately the vendor delivered that software (in part, but the significant part for this story) as compiled Perl modules. I think they maybe did that to make it harder for third parties to customize their shit, and therefore make it easier to get any related customization/integration contracts, but possibly it was just innocent performance enhancement. Regardless, though, a dude I worked with decompiled those modules and figured out how to fix the bug by doing some kind of text/encoding transform. And then it could send email.