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Losing Connection to SmarterMail Server - Connection Inconsistent
Problem reported by Bob Bell - November 11, 2014 at 7:51 AM
Submitted
I am using SmarterMail v12.4 on Windows 2012 Server Standard 64bit (IIS 8.5) with ColdFusion 11 64bit. 2 Xeon 2.4Ghz Processors, 24Gb RAM (16Gb free), plenty of disk space.
 
Problem #1 - when I reboot the server, the SmarterMail service reports that it is started up, but cannot send mail from outside (like from Outlook on my home computer) until I restart the SmarterMail service. Then everything is OK.
 
Problem #2 - emails sent from ColdFusion are being sent OK for a while, then they start piling up in the Undeliverable Folder (in CF Mail). Sample from the CF Mail error logs are below.
 
"Error","scheduler-1","11/11/14","06:38:06",,"javax.mail.MessagingException: Could not connect to SMTP host: mail.mydomain.com, port: 587, response: 421"
 
If I restart the SmarterMail service, and move the undelivered emails from the Undeliverable folder to the Spool folder in ColdFusion so they attempt to send again, many of them get sent, but then the same thing happens - the connection to SmarterMail gets interrupted and the remaining emails get moved to the Undeliverable folder. 
 
Currently, I have 9000 emails in the Undeliverable folder. Any suggestions on how to fix these problems?
Web Engineer
http://www.fullblownwebdesign.com

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Bruce Barnes Replied
November 11, 2014 at 9:43 AM
Here's a list of the tests we are currently running:
 
 
 
and here's a list of the protections they have provided to one of our customer's servers which, routinely, receives heavy attacks.  They have several international clients.

This list can be seen at MANAGE ===> CURRENT IDS BLOCKS ===> ALL BLOCKS:
 
 
 
 
 
 
 
 
 
 
The traps have significantly speeded up the customer's SmarterMail server and have resulted in zero false positives.
 
NOTE: Rebooting the server, or restarting the SmarterMail service will delete this list and it will be rebuilt as the server is re-attacked by remote hacking attempts.
 
 
 
Bruce Barnes
ChicagoNetTech Inc

Phone: (224) 444-0169

E-Mail and DNS Security Specialist
Network Security Specialist

Customer Service Portal: https://portal.chicagonettech.com
Website: https://www.ChicagoNetTech.com
Security Blog: http://networkbastion.blogspot.com/

Web and E-Mail Hosting, E-Mail Security and Consulting
0
Bob Bell Replied
November 11, 2014 at 9:59 AM
Thanks Bruce. That was the problem. My client is trying to send 400 individual emails (to her list) through a newsletter application I built in ColdFusion. After 60 get sent, it triggers the Abuse Detection = DOS SMTP (60 in 10 min).
 
What is the best way to allow her emails to get sent?
1. Add her IP to a whitelist?
2. Remove (or increase) the DOS Abuse Detection?
3. Other?
 
Thanks, Bob
Web Engineer
http://www.fullblownwebdesign.com
0
Bruce Barnes Replied
November 11, 2014 at 1:56 PM
I would make certain that the application is running full SMTP authentication.
 
You may have to increase the number of allowed messages before SMTP is triggered, but I would avoid, at all costs, whitelisting anything.  Whitelisting is inviting spammers and hackers to take over your server.
Bruce Barnes
ChicagoNetTech Inc

Phone: (224) 444-0169

E-Mail and DNS Security Specialist
Network Security Specialist

Customer Service Portal: https://portal.chicagonettech.com
Website: https://www.ChicagoNetTech.com
Security Blog: http://networkbastion.blogspot.com/

Web and E-Mail Hosting, E-Mail Security and Consulting

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