Hi Shamim, When the user(1) sent the message, the user (2) also received the email via email. However, when the user (2) replied to that message using email, the user (2) got back the attached error message in the email. Could you please help to resolve the issue?
After I changed the file permission to 755, it worked. Thank you very much.
One question: every time I upgrade the plugin, do I have to change the file permission? I thought I changed it the last time. Now, it appears that those file permission change was gone for some reason.