Topic: Lost connection after DATA (xxx bytes) from unknown[192.168.222.2]
==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3.2
- 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? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
Please help. I'm getting the below error from /var/log/maillog: I've been troubleshooting this for 2 weeks now.
"postfix/submission/smtpd: Anonymous TLS connection established from unknown[192.168.222.2]: TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)
postfix/submission/smtpd: 4DgZ8h5Z47z2hLWR: client=unknown[192.168.222.2], sasl_method=LOGIN, email@example.com
postfix/cleanup: 4DgZ8h5Z47z2hLWR: message-id=<firstname.lastname@example.org>
postfix/submission/smtpd: lost connection after DATA (57282 bytes) from unknown[192.168.222.2]
postfix/submission/smtpd: disconnect from unknown[192.168.222.2] ehlo=2 starttls=1 auth=1 mail=1 rcpt=2 data=0/1 commands=7/8"
The above error showed when I used outlook. It's intermittent. sometimes i can send mail
even with attachment but sometimes the email is just there in "outbox". Sending mail without attachment is perfect.
Here is the troubleshooting steps i've done:
a. Adjusted server timeout in outlook
b. Installed lets encrypt ssl certificate
c. Disabled window scaling (/etc/sysctl.conf)
d. Allowed only IPV4 (/etc/postfix/main.cf = inet_protocols = ipv4)
e. Allowed port 993/587/25 in windows firewall and in ubuntu UFW
f. Attachment size is just kb.
When sending email using outlook with 5MB attachment, the message landed in "outbox"
I've already increase outlook 2016 attachment size to 25.6MB from regedit "HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\Preferences. note also that in iredmail i've increased the attachment to 35MB.
This is the error i've got sending 6MB attachment:
Task 'email@example.com - Sending' reported error (0x800CCC0F) : 'The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP).'
You help is really much appreciated.