Unknown recipients automatically added while reply all

[arpitLandis]

I am replying to a mail, which was originally sent by me only.

So that email is in sent box folder.

When I select reply all, there is an unknown recipients automatically added in sender list.

How??

Any workaround for investigation??

Thank you.

[#2]

@arpitLandis 

Hi there, 

Same happened to me too. Have you figured it out?

In my case an unknown recipient is  automatically added in sender list, 

replacing one that should have been included.