==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Linux/BSD distribution name and version: Ubuntu 16.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.

# python notify_quarantined_recipients.py --force-all
* 1000 users are willing to receive notification email.
* + aaron@domain.tld: 5 mails.
* + accountant@domain2.tld: 1 mails.
Traceback (most recent call last):
  File "notify_quarantined_recipients.py", line 339, in <module>
    mail_body = mail_body_template % {'quar_mail_info': quar_mail_info.encode('utf-8'),
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 92: ordinal not in range(128)

====

This is meaningless to me, but users have been unable to receive quarantine notifications for several weeks.  Log shows we get to a certain point in the sending process, and then it fails.   It will stop sending at nearly the same user every time.  There is no indication in mail.log with which user the message is actually failing.