Thank you for reaching out to the Community! I already replied to your other post, but wanted to make sure you saw my response.
I took a look at your account and I do see you have two Autoresponder series currently activated. In Series 2 specifically, I see there is an email currently scheduled to be sent out 182 days after the new contacts have been added or joined your list. If this is the email culprit, you can click into Series 2, select the Actions option over on the right side of this particular email and unschedule the campaign. Once it has been unscheduled it will no longer send.
If this email is not the issue, definitely let us know and we can certainly take a further look into this. We are always happy to assist you in any way we can!