How do I identify and raise number connections for Exim?

Introduction

How can I check how many connections are being made to Exim, and how can I adjust this if I need to?

Procedure

If you see service notification that Exim is going offline, but you're not seeing any other issues with email service, you may be seeing a connection limit occurring. To check this, grep for "TCP/IP connection count" against the Exim mainlog and look at the connection count. By default, this is 100.

grep "TCP/IP connection count" /var/log/exim_mainlog

2020-07-05 06:43:42 SMTP connection from [203.0.113.2]:23956 (TCP/IP connection count = 97)
2020-07-05 06:43:42 SMTP connection from [203.0.113.2]:53678 (TCP/IP connection count = 99)
2020-07-05 06:43:42 SMTP connection from [203.0.113.2]:46424 (TCP/IP connection count = 99)
2020-07-05 06:43:42 SMTP connection from [203.0.113.2]:45122 (TCP/IP connection count = 100)

1. To change this, navigate to WHM: "Home / Service Configuration / Exim Configuration Manager / Advanced Editor"
2. Look for "smtp_accept_max".
3. Change the value to a higher value.
4. Save changes.