From: DeskNow Knowledge Base
http://www.desknow.com/kb/

Read timeout
http://www.desknow.com/kb/idx/11/154/article/

If DeskNow cannot send emails and reports a 'Read timeout' error, there could be multiple causes:

1. temporary problem with the network

2. temporary problem (or slowness) with the remote server

3. antispam measures with the remote server, which will delay response on purpouse, trying to discourage spamming servers

4. an antivirus or filtering firewall is installed in your DeskNow server or on your gateway, and it is configured to scan SMTP (mail) traffic for viruses. This can often cause timeout problems, and is unnecessary anyway, since DeskNow typically already scans all outgoing mail.

The first and usually best solution to try is the following:

in the Mail.cfg file, increase the value of the option 'EmbeddedServer.remoteDeliveryTimeout' (ex. set it to 60 or 90). This number is expressed in seconds. Do not set it too high (more than 120), as a malfunctioning remote server could cause your DeskNow server to get stuck waiting for replies for too long.

Make sure to restart DeskNow after saving Mail.cfg .

If the problem persists, and is not limited to a single remote server, disable the 'internet mail scanning' of any antivirus/firewall that may be on your Server or firewall.