'Hellmail' is the name of the letter column in the back of issues of Hellboy and related comics. While many comics have stopped running a letter column, Hellmail continues to run in the back of most issues.
The column generally contains a number of fan letters, and some comments from editor Scott Allie; though others including Mike Mignola have written as well. Allie will often thank contributors to the issue, respond to questions in letters and announce upcoming Hellboy and Dark Horse projects.
The column normally ends with a teaser image promoting the next Hellboy related comic.