Cisco ASA Disable ESMTP Inspection
Telnet to Exchange on Port 25 shows a row of Asterisks? KB ID 0000536 Problem Yesterday my colleague Ben called me over to the help-desk and asked “Have you ever seen this before?” This was what was on his screen. 220 *************************************************** Solution Usually when you Telnet to an Exchange server it gives you a 220 message followed by the “Banner” of the Exchange server, a little...
Mail Routing Issue ‘451 5.7.3 Cannot achieve Exchange Server authentication’
KB ID 0000791 Problem While putting in a New Exchange 2010 server today, I test moved a mailbox to this new site, and could not get mail to flow to the Exchange 2010 server at the clients main site. 451 4.4.0 Primary target IP address responded with: “451 5.7.3 Cannot achieve Exchange Server authentication.” Attempted failover to alternate host , but that did not succeed. Either there are no alternative hosts, or delivery...
Cisco ASA – Only Allow Mail Servers SMTP Outbound
KB ID 0000172 Problem It’s not unusual for nasty Virus’s and Malware once they have infected a machine, to set up outbound communications on the mail protocol SMTP (TCP Port 25), which can lead to your public address being blacklisted. So it’s considered good practice to stop all your clients getting mail access outbound through your firewall, while still allowing your mail server. Note: On Cisco firewall’s,...