Technical Note: How to disable SMTP client comforting in FortiClient

[Jonathan_Body_FTNT]

Description
This article explains how to disable SMTP client comforting in FortiClient.
Scope
All FortiClient.

Solution

SMTP Client Comforting was introduced in FortiClient 3.0 MR7 patch-3 (3.0.606).

It can prevent email clients from timing out when sending emails with large attachments.  As long as an email client is RFC compliant and supports multi-line server response, it should be compatible.

If an email client stops at about 10 seconds for all large emails and the email server fails to receive, you can try to disable SMTP client comforting by following these steps via the registry:

1. Edit the LOCAL_MACHINE\Software\Fortinet\FortiClient\FA_FORTIPROXY registry key.

2. Add the value DisableSMTPCc as DWORD under the key.

3. Set the value of DisableSMTPCc to 1.