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thank you, that solved the problem that had been bugging me for 3 days!
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thank you, that solved the problem that had been bugging me for 3 days!

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Recently, I have upgraded the firmware of my ASA firewall and started to experience SMTP problems. Both inbound and outbound SMTP connections are affected. <br />
On the Outbound SMTP Queue, it states that &quot;The connection was dropped by the remote host.&quot; The SMTP logs show &quot;4.7.0 Timeout waiting for client input&quot;<br />
<br />
On my firewall log, it says &quot;Teardown TCP connection 533110 for outside:213.199.154.136/41<wbr />624 to inside 192.168.1.5/25 duration 0:05:15 bytes 471418 TCP Reset-O&quot;<br />
<br />
I simply cannot figure out what is causing the disconnections. Strange thing is some SMTP connections are getting through, I am still getting emails and able to send out. This means that my firewall is not blocking the SMTP.<br />
<br />
But the delivery and sending queue is getting jammed up.
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Recently, I have upgraded the firmware of my ASA firewall and started to experience SMTP problems. Both inbound and outbound SMTP connections are affected. 
On the Outbound SMTP Queue, it states that "The connection was dropped by the remote host." The SMTP logs show "4.7.0 Timeout waiting for client input"

On my firewall log, it says "Teardown TCP connection 533110 for outside:213.199.154.136/41624 to inside 192.168.1.5/25 duration 0:05:15 bytes 471418 TCP Reset-O"

I simply cannot figure out what is causing the disconnections. Strange thing is some SMTP connections are getting through, I am still getting emails and able to send out. This means that my firewall is not blocking the SMTP.

But the delivery and sending queue is getting jammed up.

Exchange 2003 SMTP Connection Problem with TCP Reset-O

Cisco PIX is a dedicated hardware firewall appliance; the Cisco Adaptive Security Appliance (ASA) is a firewall and anti-malware security appliance that provides unified threat management and protection the PIX does not. Other Cisco devices and systems include routers, switches, storage networking, wireless and the software and hardware for PIX Firewall Manager (PFM), PIX Device Manager (PDM) and Adaptive Security Device Manager (ASDM).

Cisco

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.

Exchange

Hardware-based firewalls provide more sophisticated protection for inbound and outbound traffic than the simple Windows software firewall or the basic NAT firewalls found in routers. These devices implement techniques such as stateful packet inspection, deep packet inspection, and content filtering; and may include built-in antivirus and anti-malware protection.