==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.9
- Deployed with iRedMail Easy or the downloadable installer? Downloadable
- Linux/BSD distribution name and version:  ubuntu 18.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): mysql
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro? non-pro
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
=====

Hi All,

I'm having issue sending .xlsx attachment with error below:

<useremail@mydomain.com>: host ASPMX.L.GOOGLE.com[64.233.167.26] said:
    550-5.7.1 [178.20.144.34      12] Our system has detected that this message
    is 550-5.7.1 likely unsolicited mail. To reduce the amount of spam sent to
    Gmail, 550-5.7.1 this message has been blocked. Please visit 550-5.7.1
    https://support.google.com/mail/?p=Unso … ssageError 550 5.7.1  for
    more information. l17si1893182wrp.391 - gsmtp (in reply to end of DATA
    command)

Note: the error is intermittent, sometimes i can send excel attachment without any error.

your help is really really appreciated.

Thanks.
JunG