Org version is 9.5.2; emacs version is 27.1. The manual does not indicate that underscores need to be escaped in links (and they can't be, as far as I can tell). The latex and html exporters interpret them as the start of a subscript.
Leo
#+AUTHOR: Leo Butler #+TITLE: Bug in processing underscores in links #+OPTIONS: toc:nil num:nil * Description The link =[[mailto:ex_am...@ex.com][ex_ample]]= is expected to export to =\href{mailto:ex_am...@ex.com}{ex_ample}= but instead, we get [[mailto:ex_am...@ex.com][ex_ample]] exports to (in latex): =\href{mailto:ex\_am...@ex.com}{ex\textsubscript{ample}}= Note that a similar issue is seen with the HTML export. * Reproduction Export this file: =C-c C-e l p=.