Hi @tinhvqbk , thanks for the support request and sorry you are having some trouble.
Can you give us some more detail on how you were able to reproduce this error? When does this happen and what steps do you take to get this? It looks like it is simply a notice in your PHP error log (or in the WP_DEBUG log)?
We will investigate. Thanks!
There has been an issue opened on the GitHub repository with a request for a pull request to be submitted here:
https://github.com/Miller-Media/send-emails-with-mandrill/issues/8
This has been fixed in this pull request:
https://github.com/Miller-Media/send-emails-with-mandrill/pull/16
Will be available later today in version 1.2.1
Version 1.2.1 is released and addresses this issue. Thanks for the heads up!
