# ActionMailer: uninitialized constant

**URL:** <https://www.ruby-forum.com/t/actionmailer-uninitialized-constant/91488>\
**Category:** Rails\
**Created:** [April 9, 2007, 7:00pm UTC](https://www.ruby-forum.com/t/actionmailer-uninitialized-constant/91488 "2007-04-09T19:00:16Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![mh456](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/46a35a/32.png) [@mh456](https://www.ruby-forum.com/u/mh456)\
**Post date:** [April 9, 2007, 7:00pm UTC](https://www.ruby-forum.com/t/actionmailer-uninitialized-constant/91488/1 "2007-04-09T19:00:16Z")

</div>

Hi!

I have two Observers that call the same ActionMailer. With one  
Observer, everything works as expected. With the other one, I always  
get an error: “uninitialized constant MyObserver::MyMailer”. The  
calling line is identical in both observers. Do I have to “register”  
the ActionMailer somewhere?

Thanks a lot

Martin