We are experiencing what is becoming a reoccurring issue with our SMG 10.1-2 where randomly we will experience a message slow down on inbound messages. We do not see a build up of messages in any (inbound, delivery or outbound) queues. We do notice that a telnet session will start to become very slow updating and making initial connection. Outbound message delivery is normal. This will become worse and outbound message delivery will(may) become effected. After some time this appears to go back to normal operation (without intervention) and messages start flowing again. If we restart the MTA this seems to immediately correct the slowness and messages & connections return to normal. I have not been able to with any certainty say this is caused by excessive connection attempts using the firewall connection stats -we only have real time no logging.
Has anyone experienced similar issues -that can be associated with SMG, and do you have recommendations as to where I can look to see if the root cause is something wrong with SMG or maybe the SMG is just performing the way it should throttling in response to outside influence. As stated I do not have any firewall logs nor do I have access to the firewall interface to check its connection logs / or attempts at the time of the slowness.