Other one:

This email doesn't have any relation to wpDiscuz plugin. Even the message bodies of the emails are different. 

User is getting multiple emails of mentioning. One is of buddypress and the other one is in simple textual form. 

Buddypress:

Other one:

The solution that was implemented here is disturbing the formatting on textual emails. Like you can see in the second screenshot. 

1) I want only one email of buddypress to notify the user
2) Correct the styling of textual emails (This issue resolves after removing the code provided here)

I've also disables the settings of wpDiscuz to notify user on mention:

Please help me solve this issue.
Thank you.