Hi, I am currently using odoo version 12 and python 3.6. 

I have a problem sending out emails with attachments. With more than 4 attachments with each attachment of the size of 3mb. 

My error log: 

Traceback (most recent call last):
File "/usr/lib/python3.6/smtplib.py", line 354, in send
self.sock.sendall (s)
File "/usr/lib/python3.6/ssl. py ", line 975, in sendall
v = self.send (byte_view [count:])
File" /usr/lib/python3.6/ssl.py ", line 944, in send
return self._sslobj.write (data)
File "/usr/lib/python3.6/ssl.py", line 642,
return write self._sslobj.write (data)
socket.timeout: Write operation timed out

During handling of the above exception Reviews Reviews another exception occurred:

Traceback (most recent call last):
File "/usr/lib/python3.6/smtplib.py", line 882, in sendmail 
(code, respectively) = self.data (msg)
File "/ usr / lib /python3.6/smtplib.py", line 568, in data
self.send (q)
File "/usr/lib/python3.6/smtplib.py", line 357, in send
raise SMTPServerDisconnected ('Server not connected')
smtplib.SMTPServerDisconnected: Server not connected

Any idea why this happens and how to solve this? 

Thanks alot.