Traceback (most recent call last):
  File "/srv/app/mailers.py", line 76, in sendsay_execute_send_simple_email
    api.request("issue.send", message)
  File "/srv/app/utils/sendsay_api.py", line 165, in request
    raise SendsayAPIError(errors)
app.utils.sendsay_api.SendsayAPIError: error/email/lockerror: RCPT TO: gmail-smtp-in.l.google.com[108.177.14.26]: 550-5.1.1 The email account that you tried to reach does not exist. Please try 550-5.1.1 double-checking the recipient's email address for typos or 550-5.1.1 unnecessary spaces. For more information, go 

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/celery/app/trace.py", line 412, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/usr/local/lib/python3.8/site-packages/celery/app/trace.py", line 704, in __protected_call__
    return self.run(*args, **kwargs)
  File "/srv/regs/tasks.py", line 90, in resend_recommendation_email
    mailers.send_recommenders_invitation(recommendation)
  File "/srv/app/mailers.py", line 268, in send_recommenders_invitation
    execute_send_simple_email(
  File "/srv/app/mailers.py", line 20, in execute_send_simple_email
    sendsay_execute_send_simple_email(**kwargs)
  File "/srv/app/mailers.py", line 79, in sendsay_execute_send_simple_email
    raise EmailSendError(f"Failed to send email: {str(e)}") from e
app.mailers.EmailSendError: Failed to send email: error/email/lockerror: RCPT TO: gmail-smtp-in.l.google.com[108.177.14.26]: 550-5.1.1 The email account that you tried to reach does not exist. Please try 550-5.1.1 double-checking the recipient's email address for typos or 550-5.1.1 unnecessary spaces. For more information, go