Our ISP get "421 #4.4.5 Too many connections from your host" when sending to our Ironport C150. We want to open for unlimited connections from the ISP IP-address (only a single IP-address), but we want spam- and virus filtering for all mails comming from the ISP. Anyone have a clue how to configure the C150 for this? Thanks for feedbacks:)
For this to happen i guess they have a bad senderbase reputation, ie below -1.0?
What you can do is that you can add the IP-adress into a new SenderGroup in your Host Access Table (HAT overview) with a "Mail Flow Policy" that allows more connections from their IP-adress. Don't allow too many though if they have problems in their network, and make sure Anti-virus scanning and Spam control is enabled in the Policy settings too.
You can indentify which "SenderGroup" your ISP is connecting into and what SenderBase repuataion score they might have. Use "message tracking" in WebUI, or "findevent" in command line interface to find this out.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...