Emails stuck in sending queue are sent several times

[microvax]

Hello,
I have a problem with a customer using Outlook for sending emails
and I have the impression that something is slowing her email
sending process and making their emails to be sent more than one.

Have you ever experienced something similar?

 

[cPRex]

Hey there! The short answer is "no" - I wouldn't expect a tool to send a message multiple times.

Can you confirm the message was sent multiple times in the Exim logs? As in, there is a unique transaction for each message?

 

[microvax]

I detected this error message in the EXIM log file

SMTP connection lost after final dot

This happens when SpamAssassin scans for outgoing messages. I disabled it and all mails are being sent now. Before, long messages don't get delivered. It's like a timeout issue. Any advice where to check and which configuration to update?

forums.cpanel.net

As well as this
64175 refused: too many connections

I saw the "SMTP connection lost after final dot" message
before (2/3 weeks ago) so I disabled the scanning of outgoing emails form spam.
So now I don´t know the reason of this issue.

 

[cPRex]

I wouldn't expect either of those things to cause a message to be sent twice. You're specifically looking for a unique mail ID going to the recipient in two separate Exim transactions. If you don't see that, the duplication wasn't from the server side.

 

[microvax]

I discovered that "SMTP connection lost after final dot" messages
are appearing again in EXIM log files and the associated IPs are related with other messages like these
50416 refused: too many connections
9475 refused: too many connections

However they don´t appear at the same time :/

 

[cPRex]

Right, I wouldn't expect those to be related to this particular issue at all.

 

[microvax]

I have just increased the value of the "smtp_accept_max" variable according to this document:

Setting Up and Troubleshooting SMTP in cPanel | cPanel Blog

Learn how to set up an SMTP server on cPanel to send email. We look at how to set up SMTP and explain troubleshooting steps for the most common SMTP errors.

blog.cpanel.com

We will see if this change solves the problem